One of your best, Carlyn, and that is saying something. It contains some of the basic relationship checks everyone should practice.
"Love is not always enough" - You have to be able to live with them, too. Live with them as they are, not as you'd wish them to be.
"Similar childhoods" - I'd often wondered how my wife and I fit so well together when we come from VERY different backgrounds: half a world apart, different languages, different cultures. Some years ago I realized how very similar our childhood traumas were (including culturally from opposite sides of the iron curtain). How those traumas gave us very similar values and drives.
"Mutual support" - that wedding vow line "for better or worse, for richer or poorer, in sickness and in health" better be there, because into every life a bit of rain will fall.
In all these I've had both good and bad experiences, but your checks are spot on. Great read.