I had the urge to draw something silly and fun.. whats sillier than a silly face! I wanted to loosen up my mark making and think less about what I was doing. A lot of the time I over think my pieces, which can sometimes lead to work being overly processed and losing its 'pizzazz'...
Here's a quote I found a little while ago which encouraged me to just go for it once in a while:
Don't think. Thinking is the enemy of creativity. It's self-conscious, and anything self-conscious is lousy. You can't try to do things. You simply must do things.