A comedian dies and goes to heaven. There he's put in a room with other comedians.
He takes a seat. The someone calls out '235," and everyone laughs hysterically.
The laughter dies down and someone else say, "1049," and likewise, everyone laughs.
Finally, the new guy turns to his neighbor and says, "What's up with this number thing?
The guy says, "Well, we all know the jokes, it just saves a lot of time if we assign them all a number. When someone calls out the number, we all recall the joke and know it's a funny one, so we laugh."
"Hmmm," the new guy says and he tries it out by yelling, "53!" Nothing.
Then he tries it again, "420!" Still nothing.
Now he turns to his neighbor and says, "Aren't those funny jokes, or what?"
The old-timer responds, "You know, some people just can't tell a joke; no sense of comedic timing."