Adults are crafting them to show-off to people from the past and connect the dots between different audiences as a way of coping with the awkwardness of collapsed contexts.
Interesting idea as to why adults do the 25 things thing on Facebook. I'm not sure about the "show off" (at least not in the ones I've seen) but certainly the connect-the-dots things seems to be happening.
Too bad that most of the templates that they are given are much more corporate in nature.