Not the Best years of my life

I guess this is for all those older alumni. I had a good time at Duke, don't get me wrong. I really enjoyed what Duke provided for me academically and I met some pretty cool people along the way. For some reason though, at graduation I wasn't overwhelmed with sadness, I wasn't counting down the days until I had to actually have responsibility, it was almost like any other day. People kept asking "so how does it feel to have graduated?" well it feels the same for now. I guess once I start work I'll wish I could have the same schedule of waking up at 11. I'm scared that I didn't take advantage of "the best years of my life". Does it really go downhill from here? Everyone talks about making life long friends in college, if that didn't happen should I expect to just have acquaintances for the rest of my life? I guess I just need some reassurance from someone who is in their mid twenties or thirties and still having or just started "the best years". I suppose life is what you make it and I thought I made college a pretty valuable learning experience and socially it was good (especially the first two years) but overall it wasn't anything spectacular. Is it me?