I had my quarter-life crisis at around the same age, but almost the inverse of what you describe. I spent my 20s coasting through undergrad and coasting through

I had my quarter-life crisis at around the same age, but almost the inverse of what you describe. I spent my 20s coasting through undergrad and coasting through my job (read: not caring much about it). I was primarily focused on friendships, dating, and just generally having a lot of fun. Then I hit my late 20s, and after numerous flings and half-serious relationships, I got into a relationship with someone who totally shifted my perspective. I suddenly became extremely ambitious and focused on my career, and stopped the partying and fun-seeking completely. Now I'm chasing the start-up dream and what I feel like most of my peers were focusing on in their 20s.