We already know from scholarship that Ludwig Wittgenstein, the ordinary language philosopher, liked going to the movies. I'll bet he'd have liked this movie in particular, as it takes everyday templates we're familiar with (from other movies if not from personal experience), and twists them around in curious ways (like Wittgenstein did in his investigations), thanks largely to the ludicrous spin added by Steve Martin's "jerk" character.
For example, in the midst of romance we often encounter speeches about time dilation, as in "hours seemed like days." The Jerk has a long soliloquy of that nature, appropriately delivered to his sweetie in bed -- except she's completely out of it, unresponsively corpse-like, while his account turns into this long and tedious chronicle that quickly loses its romantic edge and takes us into yet another twilight zone, a language game gone off the rails.
Another template: the rich man becomes a prospect for charities looking to fund their causes, and the fund raiser shows up with some moving propaganda, hoping for a big donation. Cruelty to innocents is the theme. I see from the credits that Steve plays the cat juggler.
In another scene, Carl Reiner, the movie's director, plays himself.
Part of the humor here is Steve Martin looks so "normal" in a 1950s Pleasantville kind of way, typified by that pipe smoking icon Bob Dobbs, or by Dick Van Dyke. "How could someone who could so easily pass for normal be so off the wall?"