Time passing

I posted the other day about the strange necessity of summing up a year in a Christmas card: how can we convey the ways in which time has changed us?
This morning I've been rereading Sir Gawain and the Green Knight and found the following line, which expresses just what I have been feeling:
'A yere yernes ful yerne, and yeldes never lyke;
The forme to the fynisment foldes ful selden.' (SGGK 498-99)
The Everyman edition translates it thus: 'A year passes very quickly, and never gives back the same; the beginning is very seldom like the end.'
I couldn't (and didn't) say it better myself!