At three o'clock last night, my phone suddenly vibrated.

It's a buddy I haven't been in touch with for a long time.
The kind of person who brags the most in the group, often showing off profit screenshots.

He only sent five words:
"I'm done, really."

I thought it was another altcoin going to zero, or that the leverage was set too high and got wiped out in one wave.
Open the chat box and get ready to offer some words of comfort.

He said: "It's not a matter of the market, it's a matter of people."
I asked what was going on.
He types very slowly, as if each word is trembling—

"My ex transferred the money away, all the coins from three years are gone."

I was completely at a loss at that moment.
Hacker attack? Phishing website? Exchange hacked?
None of them.

It was the person he once trusted the most, who secretly noted down that mnemonic phrase after a quarrel.
Then, on a deep night six months after the breakup, I opened my wallet and clicked send.
Everything is over.

He threw me the link to the blockchain explorer.
That transfer record lies quietly there, with the timestamp, address, and amount all clear.
Where has the money gone?
The answer is written on the chain, permanently verifiable.

But you can't do anything with it.
Can't chase it back, can't change it, and don't even know how to report it.

The police will ask you: "Do you have evidence to prove that this money is yours?"
You said I have transaction records.
They said: "But now the private key is in the other party's hands, legally this is her asset."

It's that simple.
Cold and icy, like a bucket of water poured directly over the head.

---

What I want to say is actually very straightforward:

Many people think that "my coin" really means "mine."
Actually, it's not.
What you own is not the coin, but the right to use that private key.

As long as someone has seen, photographed, copied, or even inadvertently glanced at those few words,
Your "ownership" is already incomplete.

You might take a screenshot one day and send it to a friend for help.
You may have written the mnemonic phrase on a sticky note and forgotten to tear it off;
You might think "this person won't harm me".

Then, on a night when you are sleeping soundly,
Everything goes to zero.

It's not alarmist; it has really happened too many times.

I have seen too many people say "I understand security".
Turn around and store the private key in the cloud