Young comedians are always looking for an audience to practice on. That's one of the reasons that comedy clubs can exist, because they'll work for almost nothing just so they can practice their skills with a real audience. They get it for free when they're in school, if they're brave enough. But from then on, they have to rely on friends, customers where they wait tables, or whatever they can get. Many videotape themselves, or work in front of a mirror. Many hang out on the internet, writing snarky comments.
Actually, my favorite jokes are ALWAYS funny to me. "Jokes" can be told and retold, with changes and variations, and often remain funny. Humor is much more than just jokes, though.
