Realize that programming is an incredibly broad field, so you're absolutely guaranteed to run into many areas in which you have no experience yet others have achieved expert status. Feeling inadequate is normal. As mindcrime said, don't sweat it. Nobody knows everything about every area of programming.
IMO you should decide what you want to do in more concrete terms. Being a "good" programmer can mean a lot of things. Do you want to become an expert in some specific area of computer science, i.e. machine learning? Do you want to design your own language? Or an OS? Or your own framework? Do you want to be the ideal super-productive jack-of-all-trades startup first-hire/tech founder? Do you want to strive for the broad knowledge, wealth of experience, and leadership + mentorship abilities of an effective CTO? The list goes on.
You can't have it all. Pick one, or pick a few. Then spend years challenging yourself, ideally working on real projects that are meaningful to you, alongside other great programmers who give you something to aspire to.
IMO you should decide what you want to do in more concrete terms. Being a "good" programmer can mean a lot of things. Do you want to become an expert in some specific area of computer science, i.e. machine learning? Do you want to design your own language? Or an OS? Or your own framework? Do you want to be the ideal super-productive jack-of-all-trades startup first-hire/tech founder? Do you want to strive for the broad knowledge, wealth of experience, and leadership + mentorship abilities of an effective CTO? The list goes on.
You can't have it all. Pick one, or pick a few. Then spend years challenging yourself, ideally working on real projects that are meaningful to you, alongside other great programmers who give you something to aspire to.