[barrucadu]

Maybe this is one of those things that's harder to understand if you have an accounting background. As someone without an accounting background, I found it incredibly intuitive: if money moves out of an account, that's a posting with a negative number; if money moves into an account, that's a posting with a positive number; a transaction is a set of postings that together sum to zero, indicating that no money has been created or destroyed out of thin air.

There's no need to learn any confusing "credit" or "debit" jargon, you just need to think about the movement of money (which you had to do already).

[kinleyd]

I don't think that is the case. I think it would have to take a deeper understanding of double-entry accounting to really appreciate its genius. The key lies in the double entry that is made for each transaction. While each entry is simple, the beauty lies in how it provides the basis for detecting errors even in very large datasets simply by comparing totals - they must balance. In this context negative numbers do not provide any meaningful information at all.