Letting go is a skill, an art. And saying 'Sorry' follows in its footsteps. A couple of years back, I was in a situation in which neither party was wrong or right. The tussle, the barbs flung at each other were at best, situational. Even after two years, it was gnawing my insides. I decided to take action and took the first step. Clearly, firmly and intentionally. This was a professional space, but none of us now worked at the same company. Yet, I did not want to hold any grudge. And instead of waitiing till either of us had to say 'RIP...', I said 'sorry' while we were both alive.
The response though not immediate, did come. The other party also had decided to accept my olive branch. A dead weight was off my chest. And I was breathing easier, smiling more.
Say 'sorry' - it doesn't take much and it feels wonderful, later. :)