Yes, 'ko', the state where everything repeats, is the main symbol, though the game of go is used a lot to explain how their relationship goes on. I think that for them, the time they could have (if they dared seize the chance) would be endless and infinite, but in the end it would lead to a deterioration of what they are, because in a ko situation, you have to resolve the issues around it, else you will be stuck in the same situation over and over....
Re: someone said "murder your darlings"...