For example, I may or may not have a large amount of bitcoins stored in my brain right now and no one can take those from me without my permission. I could wash up on a beach in a foreign country, with tattered clothes, without ID or any other personal belongings, and if I can gain access to a computer with an internet connection I could still access my stored value.
If you lose your memory (though highly unlikely) you might be in trouble. I decided to keep mine on paper in a fireproof safe, so my descendent can access it in the event of my demise.