That is so last year

I know I just posted a funny kid conversation but this is classic. This is part of the conversation between Lillie and Joseph this morning over breakfast:

Lillie: That is so last year (talking about Joseph's regular butter and maple syrup choice over her peanut butter and strawberry syrup preference)
Joseph: What does that even mean "That is so last year"?
Lillie: It means it isn't popular anymore. That is what they did last year.
Joseph: Whatever they had peanut butter and strawberry syrup last year, they were invented in the 90's.

I love listening to them when they don't know you are listening...they say the funniest things. I guess I will have a lot of time for that since to day is the last day of school. Oh I hope I am ready for this. I think I can, I think I can, I think I can...I can right?