I have this problem when my anxiety is out of control. If I'm feeling overly stressed out, tired, or overstimulated, I get to the point where I can't remember daily activities and end up forgetting majorly important details. I'll start heading to work without shoes, or I'll promise a customer an item online and then completely forget that I had a customer waiting on me for the last two days. I also cannot remember words and will stutter painfully until I come up with a solution.
Even though I'm not 100% that I'm autistic, stimming tends to help me keep my focus, and of course eliminating my stress.
Try including 3 or more of your senses into your daily activities that you want to seriously remember, if you can. The more senses you incorporate into what you're doing, the better your mind can stick to it.
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~Lu