This describes me in a nutshell as well. I also like knowing exactly what I have, and where every major component is along its lifecycle. Extrapolating from that info tells me approximately how much I can rely on a vehicle to complete whatever mission we have for it, be it driving to the store or taking it on an Alaska highway odyssey. I maintain both of our Yukon XL's to a level such that I wouldn't hesitate to leave on a 7500 mile trip tomorrow morning with either one of them.for me I am sure it is the heat, it was a Nevada vehicle and it's gets just as hot or hotter there as it does here in the central valley, plus I drive it like I robbed a bank most of the time so I am sure that is a factor as well.
most resources say radiators have a 5-10 year life span, I tend to go by the lower end of that.
I do a lot of pre-emptive maintenance based on previous experience which may or may not save me any money I can order the part or catch it on sale and do a majority of it myself instead of breaking down and getting reamed somewhere or wonder why all of a sudden it needs $2000 in repairs..... learned my lesson years ago I guess.
plus I like to tinker a litte bit from time to time. I told my wife I used to have like 6 cars, lol she doesn't understand