There's a version of knowing something that feels like understanding but isn't.

I had that version of Bitcoin.

For a long time, I could talk about it confidently. How it works. Why it matters. What makes it different from everything that came before. I wasn't making things up. But I also wasn't telling the full truth — because I didn't know it yet.

I was describing the car by pointing at the wheels. I had never looked inside the engine.

Seven weeks ago, I joined the Btrust Builders Mastering Bitcoin self-paced cohort. I expected to fill in a few gaps. What actually happened was different. The gaps were bigger than I thought. And the things I assumed I already knew were often the things I understood the least.

Chapter 1 Should Have Been Easy

I expected Week 1 to be review.

It wasn't.

The first thing that stopped me was double-spending. I had explained it before — Bitcoin stops you from spending the same coin twice — and moved on like it was simple.…