Tool selection using mouse requires Escape key first

At some point within the last 6-12 months I noticed that in order to switch tools in the toolbar, I have to now hit escape first, then click on the next tool. Otherwise I can’t change tools from the toolbar using the mouse- the newly selected tool never highlights or changes until preceded by escape. Restarting computer does not help. It used to be an intermittent problem, but now it is continuous. This is on my Mac, OS X Yosemite 10.10.3.

My guess would be you futzed with Universal Access accidentally, but I’m not finding anything obvious. I’ve never seen this.

At the moment it is operating normally, however for the past several weeks it was requiring the escape key.

what is Universal access? can I make an adjustment there?