There aren't a whole lot of laws around lighting the Chanukah menorah (especially as compared to just about everything else in Judaism). But, one of them is that the candles should be large enough (or, there should be enough oil) to ensure that the lights will stay lit until at least a half-hour after nightfall. But, oddly, if the light goes out before that 30-minute mark, we aren't obligated to relight them.
There's no obvious reason for this. On Shabbat, once you've lit the candles (and said the blessing) it's forbidden to light any new flames, so it makes sense that we can't relight a Shabbat candle if it goes out. But, why not Chanukah? There's no prohibition against lighting a flame or anything like that during this holiday.
According to Rabbi Nahman of Bratzlov, it's a reminder about our own limitations. The reality of the world is that, very often, our attempts fall short. We have the best of intentions, and we try to do something helpful, or necessary, or holy. We try, but we fail. And, if we're normal, well-intentioned people, we feel bad about it. We may even beat ourselves up about it.
But, Nahman teaches, God sees our intention, and God cares about our intentions more than God cares about our results (B'nei Yissachar, Kislev 3:11). God knows that our limits and imperfections were given to us; the only thing we can really control is our effort, and our intention.
Light a candles that can last into the night. Light a candle that should last into the night. A candle that will last into the night, guaranteed? Can't promise that. Can't, and don't have to.
That's good enough for God. That's good enough.
Chag Chanukah Sameach--A happy Chanukah to you all!