I don't remember if I wet the bed when I was a kid. Well, once I wet my parents bed, but in my defense I was sleep walking and thought it was the bathroom. Anyways, my point is that I don't think I ever had rubber sheets or the things like that to prevent any permanent damage.
I am 30 and I have a plastic liner on my matress. It's not for me (I know, you're thinking "Sure, Bron" but it's true) it is preventative measures for a dog who hates me.
Monty is a problem child. He is super smart and catches on to instruction quick, but has behavioural issues that make me insane. We were away for the weekend and when I returned home, I had to go work nights. Monty hates when I work nights. I guess he's already feeling abandoned by Dad or something. So, I came back from my night shift to find the entire bottom 3rd of my bed soaked in dog pee. I thought I had shut the door, but forgot.
What I had to do at 8 in the morning was drag my matress into the tub and wash the bottom third. And then drag it into my room to let it dry. Not what I wanted to do when I was super tired anyways. Then yesterday I had a meeting in Saskatoon. I thought I shut my door but now I remember I had to get something else and forgot again. And... he peed on the bed as it leaned against the wall.
So, now I have a plastic table cloth covering my bed to prevent having to drag it into the tub anymore.
It only crinkles when I breathe.