What one tool or technology have you been unable to really understand?

NFT. I get the ledger part. And to my understanding it's digital signatures using a blockchain as a certificate authority.

But why is it only used for digital assets? Why not use it to double sign a physical asset like a house? You get the paper sig and the NFT in case you lose the deed.

EMACS. Still trying to exit, but I think I'm stuck in VIM now.

All kidding aside. Blockchain, I'm actually working on a project right now, I just don't get it.

Quantum computing