Posting under a throwaway account. I have both an MD and a PhD, and yet I struggle with very much the same thing you describe. I spent most of my life building

Posting under a throwaway account. I have both an MD and a PhD, and yet I struggle with very much the same thing you describe. I spent most of my life building my career (it's still a work in progress), and every now and then I realize how don't know -- not just about world history, languages, art, philosophy -- but also about basic ways through which people enjoy their lives. I've always felt like an idiot around people who have well-balanced lives. I didn't watch TV so I knew nothing about shows, or sports, or social media. I read a lot, but it was mostly about medicine, so I had few ways to connect to people outside of work. I had few friends, and though I was "accomplished", depression was my constant companion. My solution is ongoing, and has been to deliberately set learning goals for myself. I actually carve out time to read up on topics I want to learn about, that are outside my usual range of interests. In my case, anything I really want to do has to be planned and scheduled, but that only forces a discipline on myself to actually follow through, and helps with time management. I've always been interested in art, so I'm slowly building up my knowledge of art history. I'm taking up guitar (in in my 40s, so it'll be slow going). However superficial it might sound, I'm making an effort to learn things that are also of interest to other people. This makes it easier to connect with other people, and make friends. Tl;dr: the feeling that you're under-accomplished is probably common. Setting yourself learning goals, and not spreading yourself too thin, can help.