What makes a successful marriage?

Funny little story: when my parents were on honeymoon, my mum burned the toast at breakfast one morning. "Don't worry darling," my love struck dad said, "i like it that way." He promptly forgot all about it. Years later, I think it was 1998 or so, the whole family is around the breakfast table, and my mum brings us toast. Everybody's is done perfectly, except for my dad's. He and mum were having a rough patch at the time, and this morning he was pissed off. So he says, "how come every time you make toast, i always get the burned pieces? What about giving some of it to the bloody kids?" And my mum says, "but dear, you told me you liked it like that!" She'd been deliberately burning it for 28 years or so. Not sure which is more amazing - my dad’s failure to communicate for three decades or my mum’s dedication to burning his toast and nobody else’s for three decades.