Relationships have always been bridges for me, but when in them, they felt like solid ground. Only looking in arrears was a I (later) able to see them for what they were: bridges to the next one, which have almost always been better. The lessons learned in the expired relationships (they don't "fail", but expire) have helped on each subsequent one. I can't look back on previous friends and girlfriends and regret much of anything cause it's gotten me to where I'm at now. 16 years together, a total of 5 fights ever (if that), and always excited to see her. The secret seems to be, we've done things that work for us and make the most of the time together. Last summer, coming back from Clearlake on highway 20 (to I5), I was in "there's no cell coverage" mode...people can't call us in and we're in a fast car. She was fully encouraging it; passing everyone everywhere and hauling through for the 30 miles or so to the highway. We still laugh about how gnarly the drive was and glad we never saw anyone on that road again....and she was all about it.
Eventually, if you keep trying, the right person at the right time comes along....and it changes a (single) guy.