Current third years, what's the biggest regret of your college life?

Mine is being overly involved in extracurricular activities and running behind achievements mindlessly, which fetched me some good stuff, but I still feel there's a huge part of what I perceived a cool college life to be that seems missing from my story. I don't have many friends; the ones I had have drifted apart. No relationships, no great breakthroughs, no crazy stories to tell. But I guess that's just life, and looking back, how almost previous five have passed in a blink, maybe the end to this melancholy is near