Great question! Hashcash was actually one of those concepts that confused me too until I found this incredibly clear Hashcash https://paybis.com/blog/glossary/what-is-hashcash/ explainer. The article does a fantastic job comparing it to a 'proof-of-work stamp' - like how you might need to solve a puzzle to send an email, which prevents spammers from sending millions at once. It walks through how this simple idea eventually inspired Bitcoin's mining mechanism, but without getting bogged down in technicalities. What really helped me was their analogy to physical postage stamps - showing how Hashcash created 'digital postage' to prevent abuse. Might be exactly what you're looking for!