You can use software that allows you to create a wallet with a seed phrase of 12 words.
It's not impossible to remember 12 words if they are very important. This way you can keep the wallet in your brain. Also known as a bitcoin brainwallet. No one can steal your thoughts.
In cryptography we trust (& verify).
I have considered a 'brainwallet' before but I think the key is to refresh those words regularly
as in to make sure you are remembering the correct words.
In the case of war where you have to vacate you home or that you cannot actually get to
your home a brainwallet is the only thing which is going to save you.
Another idea is if possible create your own seed phrase from a favourite book, say
the last 12 words in the last sentence of the last chapter, all you have to do is remember
which book.
In a critical situation, the last thing I would count on is my memory.... believe me - stress, contusion, injury - and memory is VERY likely to fail. And that's synonymous with "I've lost my wallet forever." It is necessary to have an alternative mechanism for storing critical data - for example, mail systems of large suppliers (Google, Microsoft,...), perhaps (additionally) - trusted people outside the risk zone. In short, it is necessary to have 1-2-3 alternative options, in addition to faith in your memory..... As practice has shown, for example in Ukraine, which suffers from terrorist shelling of peaceful cities by the Russian terrorist army, our peaceful cities are shelled at night, when everyone is asleep, and after a ballistic missile hits a residential apartment building - you will hardly have time to collect a laptop, papers, something else to save them... there the question is a fraction of a second... Terrorists hit civilians in volleys. And if you leave at home an iron plate with engraving, and your city will be captured by Russian terrorist troops, for example - your home will be looted, and they will steal everything - purses, jewelry, worn underwear, toilets, any incomprehensible and beautiful, p.... We have met with this... So -