One of the parenting kernels of wisdom that I picked up when my kids were small was that "sleep begets sleep." What that meant was that if your baby is sleeping well, often, and regularly, that he/she will sleep more. The whole "keep her up late, so that she'll sleep later in the morning" philosophy is not so successful, until they get to be teenagers, that is.
I think that funny begets funny as well. You know how you sort of play off the strengths of the friends whom you are with? I have a couple of girlfriends who really make me laugh. And in turn, I make them laugh. One of them is coming over tonight. Our husbands are going to be at the monthly men's Bible study our church has recently started and we are going to watch My Big Fat Greek Wedding (which you must see if you haven't already) and eat salad. And maybe popcorn. And definitely some Hershey's Truffle Kisses, a delicious limited edition flavor (which you must eat if you haven't already).
Anyway, I can guarantee that we'll laugh--at the movie and at each other. I don't know if it's really that funny begets funny or if it's similar to the fact that competing against a worthy contender steps up your athletic prowess (not that I would know anything about that). The end result is lots of laughs, which equals a really good time, at least for me.