This is primarily talking about state dependence with ADHD medication (stimulants).

State dependence is when information that is learned while taking ADHD medication is difficult to recall when not in the same physiological state (when not on ADHD meds).

I started taking Vyvanse about 7.5 years ago, and at that time I started learning so much more than I ever have. I hyperfocused on computers, learned how to program in multiple programming languages, I learned a lot about Linux. During that time, I also learned a lot about 3D printing and mechanical engineering, and made a lot of cool things. About 2 years ago, my tolerance to the meds reached a certain threshold where I stopped being able to recall all the things I have learned.

When I take double my prescribed dose (which I am not advising you to do), I can reach that state of clarity and recall everything again, but only for a few hours, and then I crash lasting a few days. It's not healthy for me to continuously do this, and my dose is already too high for my doctor to raise it anymore (90mg concerta).

Today I read about state dependence in a wellness book that has a section about stimulants and ADHD, and it explains why I can't remember or do any of the computer-related things I used to do. I wish there was a way to recall all the information I've learned without having to raise my dose or use any sort of substance. It's really a pickle of a situation.