The more you know, the funnier life is.
So much of humor is based in juxtaposition or the inversion of expectations. Obviously, you have to have expectations to invert them! Other times, what will tickle your funny bone is a bad pun or a literal, absurd translation of a common phrase / information / fact / etc. You have to "be there" to get these jokes. Pop culture jokes become irrelevant and obscure with surprising speed.
Many jokes rely on common knowledge, whether it be of history or a public figure. For instance, there's a great Far Side cartoon, which sadly I couldn't find online, which depicts the Great Sphinx in Egypt with two workers peering over the head and the following dialogue:
"'That's fine,' I said. 'Good nose,' I said. 'But no, you had to hit the hammer on the chisel one more time.'"
This isn't particularly funny unless you're already aware of the fact that Sphinx is missing its nose.
When knowledge gets a bit more obscure, the opportunity for humor continues to expand. Recently, there was a very fun discussion on my Facebook feed when I noted a typo in my textbook: "tart-eating apples." So ... what ... small pastries chewing on Granny Smiths? My geeky writer friends and I had a blast rewriting this phrase with different punctuation. None of this would be funny if you didn't know the applicable grammatical rules. (Now that I think about it, technically, "Eating, tart apples" would be correct, because "eating" and "tart" are two independent adjectives describing the same noun - apple - but it definitely doesn't pass the clarity test ...)
I had a bit too much fun with this in Who Wants To Be A Hero? - a lot of jokes aimed to various levels of mythological knowledge. Zeus gets parodied; there's some snide commentary about divine family trees; and I mock Beowulf. A lot.
Sometimes, knowing a little more gives you the ability to laugh at others - be kind, please! I was in a fantasy writer's session when a panelist admitted that, when she drew her first world map of an island, "There was a river running straight from one side to the other," and most of the room laughed: either they knew the geographic likelihood of this (extremely unlikely), or had probably done the same thing as a young writer, or both. So really, we were laughing with her.
I think most of us would like to keep learning all of our lives. Isn't it a great benefit that it gives us more opportunity to laugh?