David M., 44, asked on Thursday what his own family vault actually does — a question he had been quietly avoiding since the day he set it up — and received, to his visible alarm, a clear and complete answer.

He learned, in plain English, who can spend (the family together), when his wife could reach it on her own (after a waiting period), and how recovery works if a device is lost. He had, until that moment, been describing the arrangement to relatives as "very secure, trust me."

"I built a thing I couldn't explain," David admitted. "Now I can explain it. This is somehow worse, and also much, much better."

A vault you can't explain to your family is a vault your family can't use.