system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it that couples who are trying to have kids have to have sex multiple times before successful, whereas people who have one night stands often end up pregnant?

Is there any truth to this, or is it just a way to scare people into using condoms?
gpt
I think it's more a matter of what you *hear* than of what actually happens. People who get pregnant from one night stands, and couples who are trying to have kids, tend to talk about it more than their opposites. 

Idk if there's something about people who have multiple one night stands increasing their statistical chances of getting with someone with a high fertility rate, whereas the couple trying to have kids are dealing with the same fertility rate consistently.

Or, you know, Murphy's law.