Bip39 Split Mnemonic. Theoretically, you can think out the mnemonic phrase by his own, but It's not at all Safe and sound, for the reason that a human are not able to do an awesome task with the random technology. The ultimate way to safe just one’s wallet is always https://lukaslwhtd.wikikali.com/1003065/the_anatomy_of_the_bip39_phrase_entropy_words_and_phrases_and_protection