Double booking

I recently booked brunch on this Saturday with my hubby's family for Mother's Day. Only to realize that I had already bought tickets to go see my niece at her concert on Saturday. Both are happening on Saturday at exactly the same time. Now why does that happen? I swear you can go days without anything, and then have 40 things to do on one day.... All at the same time.
Anyways, concert trumped brunch. Only because I promised her first. And Hubby can go to brunch without me.
I am looking forward to the weekend though.