From CityWendy's "The Big Day":
"Hey, you know what the difference is between a 40th birthday party and a 30th birthday party? At the 40th, half your guests have to get home early to relieve the babysitter. That's ok; more Sangria for us!"
And that's because we live in New York City. Back in North Carolina, that's largely how the 25th birthday party works.