It really depends on what I’m doin! If I’m at my computer or something I’ll just keep them on. I’ve gotten used to the lack of sound over the years. It was really jarring the first time I used Active Noise cancelling so the passive of closed backs really worked for me whenever I needed quick isolation.

It’s really just passive sound isolation. A good quality headphone will clamp around your ears to create a seal where no air can escape, therefore, no sound leakage in or out. Because that happens, the ambient noises you’re used to with open backs, have been cut out and now it’s closer to a “silence”. Since you were so used to ambient/background noise leaking in with the open headphones, it can be a bit strange to hear “nothing” now that you have a seal around your ears!