The downside to carrying cash

I carry cash. This is not something that a lot of people do now. Most people use Debit or Credit for everything. I noticed it recently when I stopped at Tim Horton's for breakfast one morning, and there was no lineup! That is very unusual. The reason? The Debit machine was down, and they were accepting cash only. I breezed through the drive-thru, and paid cash for my breakfast in record time.
However, one downside to carrying cash is that you don't really look at your change when you get it back. So, you are faced with the following dilemma...

One is a Canadian $2 coin. The other is a Dominican Republic 10 Peso coin. I must have received the Peso coin in my change at some point. And, the thing that really sucks? The Peso coin is worth about 24 cents Canadian. Damn!