A brain wallet is a method of storing cryptocurrency by memorizing the seed phrase or private key rather than writing it down or storing it digitally. The concept relies entirely on the user's ability to recall a specific sequence of words needed to recover their funds. While it eliminates the risk of physical theft or hardware failure, brain wallets are widely considered extremely risky because human memory is fallible, and forgetting even one word can result in permanent loss of funds.
Example
“He attempted to use a brain wallet by memorizing his 24-word seed phrase, but after six months he forgot two words and permanently lost access to his Bitcoin.”