Something that still trips me up is InDesign’s use of the command key. Back when I was using Freehand, I never switched to the arrow tool. I always had the text tool or pen tool selected. I’d just hold down the command key anytime I needed to use the arrow to select or drag something. As long as I held down the command key, I’d have the arrow cursor. Release the command key and it would go back to whichever tool I had selected.
InDesign has this same feature, which I appreciate, but for some reason they’ve doubled up on the function of the command key. Not only does holding the command key change your cursor to the arrow, it also allows you to select an object that is underneath the currently selected object. Every time I use InDesign, I make the mistake of holding down the command key to change to the arrow tool, holding down shift to select multiple objects, then clicking and dragging one of the selected objects. Instead of moving all of the selected objects as I intended, I end up moving an object underneath the one that I clicked and losing the selection of the objects I wanted to move.