Dirty Walls...
or something artsy about how kids mindlessly leaving stickers on walls are fantastic memories of them growing up and how they will never ever be that age(and silly) again.
In a time before kids, I remember visiting the homes of friends who had kids. Unless they were extremely OCD, their home would succumb to a scourge of stickers and ugly kid-grafitti.
I am now a proud owner of that kind of home.
P.S. Oddly, this whole sticker-parasite thing that is happening in our beautiful not-planned-for-kids space reminds me of Ta Prohm in Cambodia.