Can we just pretend yesterday didn't happen?

itbegansasofnow

Seriously though, yesterday was terrible. Great day, terrible eating. Like I don't even want to tally up the calories terrible.
It was a friend's birthday, and it involved things like cheesecake and fast food... all day. And like no exercise.
What do you do after a day of crap like that? You can't really undo that sort of thing right? And how much of an impact do you think it'll make?