Show/Hide Bounding Box

The bounding box is the part of the move tool (V, the black arrow) that allows you to resize your entire object as opposed to one point at a time.  It can get turned off by mistake sometimes leaving you wondering why you can’t resize objects.

It’s a simple toggle – Command-Shift-B (control-shift-b on windows) or from the View menu choose “Show Bounding Box” about 2/3 of the way down the menu.