Mental Exercise

This is something I have been thinking about for a long time, but I thought would lay it out here.
Since my surgery, my muscles have been really weak. They atrophied a lot in the many weeks I was down and out. I have had to get going slowly to build up my strength again and even to help myself heal. It’s hard work.
With my depression, it’s a lot the same thing. I was so incapable of action for so long that my ‘mental muscles’ atrophied, making it difficult to function and do the things I used to do even though the depression is pretty much gone. I have to slowly exercise my brain, forcing myself to do things on a daily basis, to get back to a functional level again. And I don’t just mean mental acuity tests like logic or crossword puzzles or math or English, but the ability to discipline myself to get things done, to organize, to plan and to generally think about what I am doing. It’s even harder than physical exercise if you ask me. There are constant reminders that my physical body is not doing as well as it should, but once you’ve been stuck in a mental hole for a while there aren’t as many reminders. And besides, the part of your brain that forces you to do the mental exercises is the part that is broken!
Have any of you noticed the same kind of thing in your life? Do you have areas wherein you have allowed your acumen to ‘slide’ and not be as ‘fit’ as once it was? Do you have areas in your life where you just ‘go through the motions’ or ignore the details you once covered because you’re just too tired or apathetic to bother anymore? How do you ‘get back into shape’, or do you even try to do that?