Not sure if this is really a worldbuilding question, but here goes.
Could someone put wealth into a bitcoin and then subsequently
1) Remember the bit sequence (however long it is) that represents the bitcoin account?
2) Destroy all references to the "wallet", so the only reference to the funds is in the individual's head?
I guess it depends on how long the sequence would be.
(The notion is that at some later point in time, the individual could recall the sequence and thus (with the help of a computer and the internet) access the funds.)
It seems that the sequence of bits is on the order of 100Kb, so recalling that might be a bit of a chore.