If it makes you feel better, it is completely normal to feel this way when you are 23, smart, and ambitious. You're past the cocky know-it-all teenage years, a

If it makes you feel better, it is completely normal to feel this way when you are 23, smart, and ambitious. You're past the cocky know-it-all teenage years, and you don't yet have the experience to back up the potential that you feel. I'd tell you to not sweat it so much, but that's like telling a teenager not to worry about the opposite sex. Nothing I say will make you not worry, so just don't let it drive you crazy. I think that you are hitting the "working surface" (to use a mining analogy). In other words, you've been training your whole life to do meaningful creative work, and now that you are biting into the real stuff, you feel untalented and unprepared. OMG, there are all these holes in your knowledge! That's what happens when you work on cool, hard problems. Whether you believe it or not, you are at the beginning of your career. It is unrealistic to expect yourself to be incredibly accomplished at the beginning of your career. Developing those accomplishments is what all those years in the career are for. You aren't running out of time to make an impact. That is an illusion. Your knowledge will get deeper as you keep engaging with the problems. It sounds like you work on some really cool stuff, and I really hope that you make something amazing. Whether grad school, startup, or a job is better depends on lots of variables that are particular to what you want to do. I would say first, have an idea of what you want to accomplish. Then go scout the career terrain. You may not realize it, but you have a huge advantage that you are probably not using - you are young enough to simply approach highly accomplished people in your field and just ask them for career advice. They will generally give it to you. They won't do that when you are 50. Make sure you are getting disinterested advice though, because a prof who wants to recruit does not give unbiased advice. On the other hand, maybe that's the inroad that you need. I don't know your field, so I can't give good advice on the best direction.