I offered to help, and he agreed. So I took a bunch of papers and started doodling, just idly exploring some possibilities. Dad was puzzled; as an amateur cartoonist, he was sure his professional son is going to be able to just draw the thing right off the bat - which was what he was trying to do the whole time.
In my mind, however, being a pro means more than having more knowledge or better tools. It also (perhaps chiefly) means better problem-solving strategies. It's the ability to recognize how complex a problem really is, and finding ways of breaking it down so it can be dealt with one step at a time.
That drawing Dad was trying to make requires designing two characters, communicating the donkey's feelings (and the guy's reaction), all that while dealing with the weight and pose problems that come from one character sitting on top of the other. Add staging, donkey anatomy, composition, and the usual challenges of drawing, and it becomes clear that trying to do all that in one step, is really asking for trouble.
He got the idea pretty quickly. We sketched together for a while; below is a collection of some of the butt-ugly drawings we made. The hopefully nice she-donkey design at the top of the post, is based on these careless doodles. By allowing ourselves to explore without fear of ugliness, we were able to explore a lot of ideas before making a commitment.