What makes it easier to get up in the mornings?
Enjoyment of life!
Each day has such possibilities - meeting people, having fun, earning money so you can go and spend it, travelling, almost everything - especially when the sun is shining!
And, if you sleep with curtains closed, you would have to get up to look outside to see what sort of a day it was. Once up, what's the point of going back to bed to have to go through it all again!