Ctrl+Shift+T to reopen that hard-to-find tab you just closed. And didn't want to loose.
I'm worried this might be a harder-than-it-looks type of problem, but I've started catching myself mashing that hotkey every time I mistakenly close a tab, or realize I actually did need that open. It would make my day if it actually did what I might expect it to.
updated 2 years ago
Added in 2165