I had never maintained a Diesel engine much less a HST or tractor before I bought my first Kioti CK20 twelve years ago. I didn't do my own car maintenance either. Neither the CK20 or DK40se has ever been back to the dealer and I have done all fluid changes and replaced a couple of minor parts. I'd guess I've spent maybe 60-90 minutes a year on average doing maintenance other than greasing.
With a cell phone, a maintenance manual, a UPS truck and a cooperative dealer, I have solved every issue so far and feel I know the tractor better than if someone else did the work.
Biggest hassle: getting HST filter off the first time. Factory puts it on too tight and paints over it. Solution was bigger filter wrench. Most difficult: diagnosing why 4wd suddenly quit. Answered while talking via cell to dealer mechanic while on my back under tractor when "we" found a simple electric connection uncoupled by brush. Fixed in five seconds.
I don't consider myself a shade tree mechanic by any means but necessity (tractor is on an island and would take a day and $$$ to get to and from a dealer) has made me learn and be comfortable with the basics. And, I shouldn't fail to mention how friends on TBN have answered numerous questions and given excellent advice. If you can hold a wrench, these guys will gently talk you through the steps necessary to use it effectively.