This always happens. It's not a bad thing, just more of a funny observation.
I went to buy these:
And in passing by the tools section, I realized I've always wanted one of these:
I own a couple of t-squares, but they are all "Hobbyist" level. The main one I use has the top part of the T held in place by screws, which means it's always moving around a little, and difficult to get a perfect 90 degree angle. This should do the trick from now on. A nice little tool to add to the arsenal.