Where do dreams come from?

I’ve been told that we dream every time we sleep, it is really a matter of if we remember them at all.

I’m just kind of curious because for the past week and a half, since moving, I’ve been having long memorable and crazy dreams.

This hasn’t been typical, before this week I would be lucky if I had a memorable dream once a month.

Do you have any experiences like this or any ideas why this would happen?
I understand this could also be a discussion.