Why didn't the alcoholic became a comedian?
Q: Why didn't the alcoholic became a comedian?
A: Because he couldn't stand up.
Here is an alcoholic joke - which is to say a joke about an alcoholic. This joke also is a riddle in the standard Q and A format.
The humor in this joke is a pun, and the pun is centered around the words "stand up".
If someone is "so drunk they can't stand up", or "falling down drunk" that means that they are drunk enough that they are not even able to stand up without falling over.
There is also a type of comedy that is known as stand up comedy where the comedian performs in front of a large audience, and so the two versions of the words "stand up" are the linchpin of the pun.
Now, I have to say that it is usually not considered appropriate to make fun of people that have disabilities, and some people consider addictions to be a disability. That being said, people who are addicted to things seem to get made fun of fairly often, so this might be a loophole in the rule about making fun of people with disabilities.