How do you bootstrap it? You get robbed at gunpoint by some ruffians and they take your wallet, cellphone, keys, and laptop. Hopefully they can't get into your accounts, but never mind that, how do you get back in to everything?
This isn't that uncommon. Things like disk encryption also do this (e.g. bitlocker)
So ... a password?
Also in this scenario you've been robbed. It's quite possible that either they took your printed out passkey also since it was in your wallet, or you're not at home where you can get the pass key from your file cabinet or safe.