Actually, I saw an article once that said that, exactly because of that problem, people age differently. Specifically it said that because of this problem, Leia is 2 years older than Luke, even though they were born at the same time. That article said that Dagobah was spinning so slowly 1 month there is 2 years everywhere else. That also explains why Luke got so little training, he didn't and it just felt that way. But, I don't remember if it was confirmed by someone and if it is fake news, but it makes sense