For most cases, i would agree. But i'd like to quote a page from Bitcoin Wiki.
So for such case use https://brainwalletx.github.io/ ?Quote from: https://en.bitcoin.it/wiki/Brainwallet
Brainwallets are not recommended to be used in general because of fallible human memory. But in special situations they could be very useful, for example when fleeing a country as a refugee with only the clothes on your back.