Choosing move/rotate deselects current tool

Real basic UI question. I'm following a video tutorial, and he keeps saying 'choose translate, then click to [apply your current tool].' When I choose any of the move/rotate/translate buttons, it forgets the last tool I was using, and I have to go back and select it again. It makes shifting my view really annoying. What am I missing here?

Have look at the basics of the user interface here

with alt + plus clicks you navigate in the viewport. with W E R keys you select different transforms, move-rotate-scale respectively. Consider pressing alt as a toggle button that allows you to navigate around your scene and if alt is not pressed then you can move rotate scale objects in the scene. It might be confusing in the beginning but after a while you won't think about it at all.