There are two types of hurt. (Unintentional and Intentional).
More often than not a lot of hurt comes about when there is a lack of communication or understanding as to what one's boundaries are. If someone had no idea of how you felt about something prior to doing it then the hurt was unintentional. Making assumptions can be painful.
Every couple has hurt one another. In fact it's been said:
"Anger is the mask that Hurt wears."
Underneath it all whenever a couple has a fight or argument it comes down to one of them (feeling) hurt, taken advantage of, taken for granted, or disrespected on some level. Our fights/arguments are designed to establish "boundaries" and "expectations".
Intentional hurt is when it's clear one (knows) how their mate feels about something but they decide to do it anyway. The main reason this happens is because (they're only thinking about themselves) and what (they) want "in the moment". The majority of the time a person commits a "selfish act" its done with the belief that their mate will (never find out) about it which on some level explains their statement: "I never meant to hurt you."
(In other words: "I never thought you'd find out!")
However there are instances where people do you wrong and WANT you to know about it! Their actions are often tied to revenge of some kind or payback for some injustice or wrong they feel you put upon them. They may have "forgave you" as part of their plan.