turning 30

why is 30 such a milestone? i don't know why i don't want a big party, i just don't.
and it's not that i think i'm getting old...the number means nothing to me.
if anything it's a celebration that my 20s are finally over.
so why must everyone insist on having a party?
why is it any different than any other birthday?
and why do you think i'm going to regret not having one?