The Lights That Just Won't Be

So here's my Christmas tree when it's actually lit and fully functioning. With Corey's help I got my tree all put up, but while we were working away and just about had all the lights on, half of the tree went dark. Oh no, which strand is it? Because we're just so smart we figured it out in a jif. And then the other night while enjoying the lights, all of the sudden the tree once again went dark--with the exception of one strand on the bottom, which just happened to be the strand that was replaced. How sad is that? I guess I could go thru and check all of the strands to find out which one is the culprit but I haven't taken the time just yet. So for now and maybe the rest of the season I'll just have to remember what could have been.