I'll answer some of your questions based on what I've read and my experiences.

... they are amazing and intense, is this the case? Yes, if I wake up while one's underway.

Am I alone here in never experiencing this? Is it only a teen thing? No to both.

Do Adults get them and why some do and others not ...? Yes but the reasons seem to be unknown.

Here's a couple threads that have discussed wet dreams:

Never had a wet dream!
Wet Dreams: anyone else never experienced one?