I guess a lot depends on how often / how well you maintain the seals. Also, walking looking AND FEELING your rig's surfaces ever few months. My camper is only 2 years old and at time I'll just walk and stare and feel the surfaces. My husband, no matter how many times he sees me doing it, asks "what are you doing?" my answer is always. "Just checking stuff out." I found a potential roof leak this way and was able to stop it (I believe) as soon as I noticed it. The outer ceiling edge in the bedroom had a small wave/ripple spot, that's what alerted me, but it looks to me like there's no further changes to it. It's an area you might not look at normally, as you have to be looking upwards, which is not exactly natural when moving about in the camper.
I'm kind of a nerd in that way. Some may find it to be laborious and tedious, like they have better things to do. I find it relaxing.