I've always been an advocate that yes if it doesn't work the first, it won't in the future. That said, and I'm eating my own words here, it very much depends on the circumstances. My partner and I split up when our son was only 5 months old, we lived apart for just under two years, but for us we just needed the space and time away from one another to see the wood for the trees as we'd started going out with each other, within six months I moved in with him and at 7 months found out we were pregnant! We split amicably and we both wanted to split from one another, which I think played a huge part in our recovery. At first my partner would come and pick our son up and they would go out for the day, however slowly but surely we started to go out as a family and himself and I gradually realised there was something still there, which we worked on and eventually moved back into together in 2007. We got married last year, neither of us regret the split, in fact it is actually what saved us to be honest. We grew up, matured and worked at our relationship.
So in answer to your question honey, I think it very much depends on why you split, how much you are both willing to put in to make it work and to keep it up and whether you both feel the other one is worth it. xxx