Why are birthdays so overrated?

Hi, its my birthday today. Why are they so overrated? I don’t want to go out party or anything… It’s just like any other day. I actually want to be by myself, sitting outside smelling the fresh air and think… That makes me happier…
I never understood the importance on “doing something” in birthdays. Why? before I always felt bad that I couldn’t find something to do, so I organized huge parties. But was never satisfied, they were not necessary either.