I vaguely recall readig a claim that there are 2 sorts of dreams.

Supposedly, some are boring simulations of realistic simulations. Like waiting at traffic lights or eating meals.

While others are wild combinations of crazy factors (which probably have that 'dreamlike quality' to them).

The former ones are your brain practicing old scenarios, and the latter ones are imagination and preparation for new scenarios.

You get them in roughly equal amounts of time, but you don't always remember your dreams so your personal experience may be different.

I don't know where I read this though. It might be just an idea by a blogger, or it might be an opinion of a neuroscientist. (And even if it is the opinion of a neuroscientist, it might only an opinion/hunch of theirs, and I probably haven't remembered it 100% correct.)