How do you actually know if your Bitcoin is “clean”?

This might be a dumb question but I’m genuinely confused.

People always say stuff like:

– just don’t KYC

– use CoinJoin

– use a privacy wallet

But how do you "actually" KNOW your coins are clean?

I checked one of my (cold storage) wallets recently and it honestly surprised me… there were links I didn’t expect at all.

Now I’m thinking maybe a lot of us are just assuming privacy without really verifying anything.

It’s kinda misleading how “private” BTC feels until you actually trace it.

Is there an actual way to measure this? Or is everyone justt guessing?