If they've never heard of changing the fuel filter then they've never read the manual or looked at the dash board. Eventually the filter will clog and the truck will have no power. Then they will wonder what in the world happened.
I change mine about 10,000 to 15,000 or whenever the Chevy dash display tells me too. I carry an extra with me at all times. Once when I was really busy with work the display came on and said to change. I didn't think I had the time and kept putting it off. Sure enough, the truck's power dropped all the sudden and I pulled off the road. I put the new filter on and all was good.