One of the biggest reasons an audience isn't laughing (or why a reader stops reading) is that they have unanswered questions.

Let's say you mention something in passing, especially something really loaded like a previous marriage, a recent breakup, or the time you spent in prison.

You may have moved on to another topic, but the audience/reader is still thinking about the door you cracked open but didn't walk through. What were you in prison for? How many marriages have you had? Why did you break up? Are you heartbroken?

Mentioning something that emotionally-loaded is like putting a gun onstage. The audience keeps wondering if and when it's going to go off.

Listening is simultaneously something you use to help you make comedy, and something that COMEDY TEACHES YOU.

Every good comedian knows how to listen to an audience. Not to STEP ON THEIR LAUGHS. To be in dialogue. An audience can tell you if you are giving them a good set up but not paying off, or giving them a good punchline but not setting it up.

Quiet audiences can tell you things too. But you have to listen carefully, because there are many kinds of quiet audiences. The 'we’re too tired to laugh but we really like you' audience. Sometimes quiet crowds are the most appreciative after a show.

An audience will tell you they are restless. They will tell you something is funny sometimes that you did not even realize was funny.