I am talking about it in the sense that the original comment was, that you can’t truly have a negative amount of a thing.

The original comment notes that we use negatives as a concept, even though they don’t really exist. The simplest example of the difference is that yes, the concept of negative numbers is needed with currency and transactions, just like negatives are needed with electrical charges and waves, but at no point do you actually have negative amount of currency, you just owe more than you have, which is where we use the concept of negatives.

That’s the difference the original commenter was distinguishing between positive and negative. Positive things do actually exist, you can count the amount of dollars you have in your hand. Negative things are a concept we use in our models of things, you can’t hold a negative amount of dollars, but you may owe the bank way more than you have because of your student loans.