My 21st birthday

Yesterday was my 21st birthday. I did not spend it like many other people have when turning 21. I worked 9 hours at the office, then went home and changed, then I went and lifted at the gym (scheduled day off from running). Then I came back, made dinner, then went to the grocery store, came back, unloaded the groceries, and went to bed at 10:45 pm so I could get into the office earlier than usual today. I did not crash my bike twice or sing Karaoke like Mark. The other interns in the office offered to take me to happy hour after work, but I had to decline so I'd have time to lift and go to the grocery store and get to bed early. Is this what life is like after college?