Working Out Loud book fame, I wasn't sure what I would find. The title, The man singing falsetto in the ladies' room, definitely attracted me to reading his blog post. And when I read it, what I read was not what I expected, which is exactly what John was trying to do with the title of his blog. If you have not read the article, go read it, it is totally worth the 5 minutes it will take you to read it.
In John's blog post, he highlights that most people will make assumptions about the intentions of an action by another person. We take lots of little pieces of information in based on our observations and then fill in the rest with our imagination. Basically, what we do is fill in all the missing pieces. And by filling in the pieces, we often get it wrong.
While it is not possible in all situations, if you catch yourself making assumptions about someone else or guessing what someone is thinking based on their actions, take a step back and try to assess the full story, ask questions and be thoughtful before making a mistake based on false assumptions.
Go read the article, it is worth it and the punchline is awesome.