I'd guess the kings, clergy and nobles liked their legacy and the people generally, then as today, like to work on something that improves society. And also, t

I'd guess the kings, clergy and nobles liked their legacy and the people generally, then as today, like to work on something that improves society. And also, the average life expectancy at birth is a lot lower than the age an adult can expect to live to. People got old in the middle ages, it was just not as common, but probably more common for the aristocracy.