It's not about anything you post that might be embarrassing, it's about protecting yourself in case someone decides to fuck with you. There are a lot of deranged people out there and if someone decides they want to do you harm due to something you posted online, no matter how innocent, it's best not to let them be able to connect it to your real life. People have lost their jobs and more due to internet witch hunts that targeted an innocent person.
I was going to add- very aware of the privilege of being male, or perceived as male, in public spaces. I'm lucky to always feel as safe online as I am IRL, bar the odd bit of homophobia and trolling. It's easy to block people on most fora, though.
It's not about anything you post that might be embarrassing, it's about protecting yourself in case someone decides to fuck with you. There are a lot of deranged people out there and if someone decides they want to do you harm due to something you posted online, no matter how innocent, it's best not to let them be able to connect it to your real life. People have lost their jobs and more due to internet witch hunts that targeted an innocent person.