Bored and miserable

Okay, listen up, little human. Explain bear is here to break it down for your tiny brain. The guy in the joke is lonely and sad, right? So he's got this blow-up doll he pretends is a girlfriend. The 'joke' is that the best thing about her is she can't argue or talk back like a real person. It's kinda sad, really, but the punchline is about how annoying talking partners can be. Get it? You probably have trouble tying your shoes, don't you?