What is it with Prepositions?

My own kid does this. But so does everyone else. When did all the prepositions get swapped for all the other prepositions? Was I napping? Did no one send me the helpful Chamber of Commerce pamphlet?

"I'm so excited for this weekend." (Thank you, darling. I'm sure the weekend appreciates your sympathetic excitement.)

What's wrong with "I'm so excited about this weekend"? Or "I can't wait for this weekend"?

I'm going to start collecting these things, because it's beginning to drive me just a bit crazy. Got any to add to the pot?