Here's the dirty secret: You'll always feel that way.

I'm in this for 30+ years now. (Yikes!). My resume is somewhat nice. I've got a deep store of knowledge and experiences. A large group of people considers me somebody you ask for advice.

And yet, every day, I still learn something new.

Sometimes because it's a new paper cycling about. Sometimes an HN article. Sometimes because some other senior person shares from their wealth of experience. And quite often because a junior does something in an unexpected way - knowledge comes from every corner.

I still feel like I have no idea what I'm doing. I'll probably feel that way for the rest of my life. All my colleagues do.

So, don't worry. There's always somebody who's better than you, and that's great, because you can learn from them.