Well, with Google Chrome‘s recent material redesign (Build 69), one of the most odd mouse shortcuts that I have used since ~1995 has gone away… that is/was the ability to close a window by double-clicking on the top-left corner of the window. And since a large majority of my time on the computer is spent in Google Chrome, it’s a noticeable change.
I just updated to Chrome 69, and a dozen times now I’ve tried clicking on that corner to close windows, but now it only resizes the full-screen to a window. It’s old holdover in my brain from the Windows 3.1 days, which makes it an odd thing to still be using after all these years, but sometimes the top-left corner is just closer to where my mouse pointer is, and thus more ‘efficient’… but alas, that “secret” shortcut no longers works… in Chrome. (It does still work in Windows 7.)