Is it common for developer to loose passion to learn new things ?

I know that feeling from time to time.

What I do:
Go outside, do something really different.
Speak with other developers, especially newbie that are still in the initial learning phase.
Teach someone.
Do a quick win project, start in the morning and it should be finish at the end of the day.

Programming is not just about programming. If it was there wasn't sense on our profession.
Programming is about making other things easier automating tasks and building tools that help other people on any professional field.
It's also transversal; you need to know a bit about science because IT is a science, you'll need a bit of design and UX if you plan to be in front-end, you could also learn about marketing, psychology, other engineering basis, mathematics, physics...
And all of that will help you to code better, thinking out of the box and being inspired to do different things.
When you are in that point it doesn't matter if this "tool" you imagined already exists; build your own with your own flavor.

I'm a senior developer who coded for 10 years (near 11) professionally and I'm myself studying Design and digital creation (college grade) because... why not? I'm a full logic person that is learning about abstract concepts such colors, shapes, what those things combined can produce (sensations, feelings) on people and so and I'm enjoying it a lot and I'm able to understand why the companies build its branding that way and what can be done better and what is an amazing job.

My father once said to me: "Study whatever you want, if you really want to be on IT remember that such me (he's a very good electro-mechanic) you'll need to learn along all your life, I know you like to learn new things so keep it on!"
Then he took extra hours at job to pay me a basic web course back those days when I was 14 and we used transitional HTML, CSS 2 and very basic javascript.

This was my first experience, then I took the studies I've in my bio and now here I am, paying myself more studies instead on buying a new bike or... whatever, but you know, I'm near 30 and I'll keep the new bike thing for the 40's crisis 😆

It's something that happen with any professional field.
Doing things because you want to do that is nice, but having to do something only because you're payed for that for years and years is another thing even you like a lot what you are doing and specially if you're on a company that doesn't threat the burnout but well... this is something everyone need to fight against except some privileged people

Finally I found someone who is experiencing the same thing as me. It happens with me too. I am at 3rd year of my engineering and these past two years I have gained knowledge about Game development, hybrid app development, android development, cloud computing, blockchain, web development. Right now I'm still thinking what to do. The main thing is to stop giving excuses to yourself. I shouldn't be saying this but right now I am about to start android app development and I have to learn web developement for my mini Project too. I know I am making excuses that if there wasn't any mini project I could have started android development long back blah blah. The main thing is to just start doing things. Plug in your phone to a charger, switch it's data off so that you can't get distracted with notification and start doing the thing which you are interested in. This works in my case. As I have to do competitive programming too for my interview prep I solve atleast 1 problem in hackerrank no matter how easy it is. This improves the consistency. I'm planning to learn flask and I will be starting that from tomorrow a little progress at a time. Same goes for my android development but that will after 4days.

This happens to me, it's almost cyclical. Most recently I went to CodeMash conference in Jan of 2020 and got super motivated, building out apps with new tech; I was going to coffee shops every Saturday and Sunday morning the minute they opened, I looked forward to it all week. Then in March, when stay home order happened I lost all motivation. My advice would be, don't beat yourself up for losing it and don't try too force it too hard.

TL;DR Finding competition
I feel you. I think that I wasted a couple of years like that feeling that something was wrong. I just saw weeks passing by just doing the minimal of what I needed to do and nothing else. Eventually I was the guy who was taking technical decisions inside the company I was working for at the time. Working with CRUDs projects over and over again.

After some months, I felt sick of this situation. I told my boss that I wanted to quit, they offered me anything ($$$) to stay. But that only just worked for 6 months more. I just quit but still I was feeling that something was wrong. I moved to another city then another city. I found a job where there are a lot of people better than me. Then I realized that I still had a lot to learn.

I started working with them these guys were crazy 20+ years of experience working 10 hours a day and studying 5 hours daily. Then I saw them solving problems in minutes or seconds. That for other very competent engineers it took days or weeks. They seemed to know every possible command in Bash and Git from memory. I know it is a crazy life style but they inspired me to be better to be professional.

Since then I realized that I was choosing to live like a real professional. I realized that I was not a professional that the majority of people are not doing their best at their jobs. Very often developers do their minimal effort and when something went wrong they blame others.

For me to be like them I need to read all those Software Engineer classic books, read the specifications and official documentation of the technologies that you use. Write about programming, go to hackatons, have side projects, create open source tools, being a mentor. They are the kind of person everyone wants to work with because you learn a lot from them.

I think they make me understand that I was in my comfort zone. They make me realized that I was wasting my time and there is a long path to be a professional. Just because someone is paying you for do programming that does not mean that you are doing it well.

Maybe the tools you are using for develop are the ones you are getting tired off. It's know the js fatigue in javascript, specially in react devs who have to jump from one lib to another, every 6 months with the new "state managment library" and where every new lib it's a zero-sum thinking.
Maybe it's time to switch for more stable tools, or switch from backend development to frontend trying to find something new that you really like and want to spend your time learning. Don't go for the hype, go for what you need.

Not sure about others but it happens often, specially when I plan on contributing to a new github project at the same time try to write a blog post about web dev plus a past project I have to contribute to! Too many things and then you sort of start to lose interest and forget why you started in the first place. I like exploring and diving deep into topics specially stuff like computation and algorithms. Trying to focus on other activities and hobbies helps a bit.

Happens to the best of us!

For me the most difficult time to carry on learning is when I am already knee-deep in a topic and I realize there is still so much to learn and other people know a lot more than I do. It's overwhelming. You feel like you don't have what it takes..

When this happens I try to remind myself that knowledge goes wide, and knowledge goes deep.

Maybe if you don't feel like learning a completely new thing right now, try to pick something you know, open the documentation page and read every single, damn, freaking line. I can assure you you'll find out at least one feature no one else knows, and you'll get excited about It!

Then if you're into it, write a post about what you just learned!

Rinse and repeat, trust the process 🙂

Good luck!