So after finally overcoming my rage when playing Brain Age: Concentration Training... I have to say my concentration is actually increasing, little by little.
Playing Devilish Calculations, I was sure that three-back (remembering a string of three problems and then answering the first one asked, then adding another one and repeating 27 times) would just kick my ass forever, but holy shit I'm starting to get the hang of it. I'm averaging about 70-80%, and I need 85% to move to the next difficulty.
Then there's the Concentration Challenge, which you're only allowed to do once per day, which is just an unending string of two-back boxes (similar to three-back calcs, but instead of doing calculations, you're simply remembering the number of boxes shown) and you see how long you can go without making a mistake. I started at around 30 seconds, but now I'm almost at 2 minutes. It gets tricky when it tries to break your concentration by tinting the screen red, making the music faster, adding more boxes, placing the boxes in weird patterns to make it hard to see how many there are at a glance, etc. I'm almost proud of myself.
Then there's the card memory game, which is just the game everyone knows where you have face-down cards, and you gotta match the pairs. The only catch here is that you're only allowed to look at each card once, and then incorrectly matching that card goes against your score. I'm oscillating around level 10 and 11 at the moment, which is about 30-32 cards to remember, which is a bigger difference than you might think. But whereas when I started off getting frustrated all the time, now it's a little easier to remember the order of the cards.
I'm getting back into running as well. I can make it about halfway around my block without having to slow down and catch my breath. Maybe getting in shape is possible after all.