system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Probably been asked a thousand times, but why do Obi Wan, Uncle Owen and other characters age so much between episodes 3 and 4?

The gap between Revenge Of The Sith and A New Hope is about 19 years if I'm not mistaken. In Episode 3, Obi Wan is very fresh faced and young looking, and Owen Lars looks like he's no older than 30. So why do they look so much older by Episode 4? I always assume it was the harsh conditions of Tatooine, but other characters such as Anakin's Mother and Luke look pretty normal for their ages with no signs of wear from the planets environment. Is there a canonical or legends reason why Obi wan goes from 35/40 to 65/70 in only 19 years? Same for Owen Lars?
gpt
The deserts of Tatooine takes their toll on those who live there. Luke was only 19 when he left, but he looked like he was in his mid 20s.

I hear his Grandmother had his father at 16, and by the time the boy was 10 she looked like she was in her late 40s!