I’ve been using Adobe Illustrator almost every day for years now, so I’m always surprised when I discover something new by chance.
For instance, I constantly use the cmd-space and cmd-opt-space shortcuts to zoom in and out while working, usually by drawing a marquee around the area I want to zoom to. What I just found though is that if you draw the marquee in the wrong place (something I do quite regularly), then releasing space bar and pressing it again (keeping the cmd and/or option key pressed) allows you to reposition the entire zoom marquee. Release space again and you can continue resizing the marquee. Genius.
While playing with this discovery, I also found that after pressing cmd-space to select the zoom tool, you can release the space bar and the zoom stays active. Am I stupid for not finding this sooner?