When I was in college, I lost my scholarship one year. I had enough money for tuition, but not room and board. So I camped in the hills.
I only have so much energy, so something had to go. This is why, at the end of the day, I've preserved my sanity for the children and also manage to do my best at work.
In the end, my reasons for moving down the timeline and introducing a new cast have more to do with keeping myself entertained, on the assumption that if I get bored, my readers are going to be even more bored.

