Living with a disability can lead to a cycle of negative thinking, in which we constantly repeat discouraging mantras like “I’m useless”, or “It’s hopeless”, etc. This cycle of negativity is a mental habit, something the brain does automatically if you let it (like biting your nails). The cycle is self-reinforcing, it may get worse if you don’t actively counter it. Pushing the mental STOP! button when you have a negative thought is the least you can do to try and slow the cycle. In my own case, I add a little extra reinforcement by pinching myself hard whenever I have a negative thought. The pain goes straight to my subconscious, hopefully acting as a disincentive to even think a negative thought. Good old-fashioned Pavlovian conditioning.