Stroke affects short-term memory more than long-term memory.
Sometimes. Sometimes not. Far too risky an assumption to make.
And if you get into crash or get a heart attack, develop dementia or something terrible happens, the first question is if you survive and the second question is, if you actually remember that you have bitcoins or in best case, where you saved your seeds.
You are more likely to remember where you physically put something than a list of words you just repeat to yourself over and over. And if you forget the location of your back up, you can at least look for it. If you forget your memorized seed phrase, your coins are gone.
Memorizing isn't that hard or bad practice.
Only if you also have physical back ups. Relying only on your memory is very bad practice.