Have you ever noticed that people who don't have children never seem to grow up?

Have you ever noticed that the people who never have children never seem to really 'grow up'? They are the kind of people who fret over tiny things that in the end don't really matter. (Like having to bring their own pillow to hotels, etc....) Just an example. I am not sure how to word it, but it feels like these people are stuck as perpetual teens. Selfish to the core and unable to ever love anyone more than they love themselves.