How do people lose their bitcoin?

Accidental loss is a far more frequent security threat than hacks and physical attacks. Humans are clumsy by nature. Multiple keys help you protect your bitcoin from yourself by giving you extra redundancy.

THE WORST WAYS TO LOSE YOUR BITCOIN

There are plenty of horror stories describing how unsuspecting holders have lost their bitcoin. Avoid them, or pay the price.

https://bitcoinmagazine.com/culture/avoid-these-mistakes-or-lose-your-bitcoin