From words to keys
The words come from a fixed list of 2048 and encode entropy plus a checksum. That entropy becomes a master seed, the seed becomes a master key, and standard derivation paths turn that into an effectively unlimited number of accounts across multiple chains.
Because the derivation is deterministic, the same phrase in a different wallet app reproduces the same addresses — provided the app uses the same derivation path, which is the usual reason an imported wallet appears empty.
Why nobody can recover it
There is no registry mapping phrases to people. The blockchain only ever sees signatures, and a signature proves possession of a key without revealing who holds it. There is no account record to reset because there is no account.
This is the cost of self-custody and it is not negotiable. The same property that stops anyone freezing your funds stops anyone restoring them.
Storage that survives real life
The threats are theft, fire, water, loss and your own forgetfulness — and the common failure is optimising for one and ignoring the rest. A photograph on a phone is convenient and is also the single most commonly drained storage method.
Write it on paper and store it somewhere only you can reach, or stamp it into metal if the amount justifies it. Consider a second copy in a different physical location. Never type it into anything that is not the wallet application itself.
The one rule that prevents most losses
Nobody legitimate will ever ask for it. Not support, not a validator, not an airdrop form, not a wallet migration page, not FBT Swap. There is no legitimate situation in which the phrase is typed anywhere except into a wallet you are restoring.
If a page or a person asks for it, the request itself is the proof of fraud. Nothing else needs checking.