Well, my shift went sort of the other way. I was a pretty uptight child. I'm much more laid back as an adult. For me I think it had to do with control over my life. When I lack the ability to make decisions for myself, it stresses me out. So for me, I suspect it was more situational than anything internal, really.
Insomnia does tend to stress me out more though, so I can see how that could do it to you. And we all know how those hormones are!
I just find it very interesting and I'm curious about why changes like that happen.
