How do you do it? This is impossible for now lol because I have too many things to memorize, my phone numbers, my car plate number, my accounts number and so on, having too mamy things memorized will interfere if you take some time off and focus on other things, it's very easier to mess everything up, there is no better solution with seed phrases than to write them down.
Sometimes, fate can make things happen to you, like an accident or memory losses, this happens to so many people and it's not as if they prayed for such, it just happened out of the blue, I am not saying such will happen to you but we humans, sleeping and waking up everyday is a risk.
Kts possible for sure to remember as much as you want, some people are better than
others and regular use/exercise is important/necessary.
Repetition, repetition, repetition as Zaguru12 points out and this is only an extra
backup, not the only way to store seed phrases.
I have never tried this although I have thought about, it cannot be that hard?
its just 12 words per wallet. There are people who can remember the players
for their winning world cup team of 2, 3 or 4 tournaments ago. If you prioritise memorising
and reciting the words it shouldnt be a problem.