I spake as a child, I understood as a child ...

I have 3 children, ranging in age from 5 to 11.

With the youngest, I can sometimes get away with the 'Because I Said So' model of parenting.

Me: Clean up your room
5yr: Why?
Me: Because I said so.

Not so for the older ones. They constantly question my authority, and I have to justify my decisions to them.

Me: Clean up your room
11yr: Why?
Me: Because I can't find your little sister.

All this justifying of decisions is tiresome (it would be much simpler if they all just accepted my authority without question like my wife does).

As for tired parents, the 'Because I Say So' model for claimed authority is undeniably easier for an IDP than actually having to justify your decisions and actions. But most RPs, like all children, do grow up eventually.