SmartyPants Monthly is 100 fun questions. It's like the most fun midterm you'll ever write, all about stuff you're interested in.
Take an hour on the last Saturday of every month, send your results back, see how you did. Most people play on their own, but if it's more fun for you to play in a pair or on a team, that's fine, too. Pay what you want: recommended cost is $5/person, $7.50 for a pair or $10 for a team. But if things are tight, don’t worry about it. Become a Patron!