Single-speed... I just don't get it

I have never had the gears slip, fall off (unless the bits were knackered). Indexing took me about 30 minutes to figure out, and is turning the H and L screws the right way, really that difficult?

Sorry, I had to chuckle at this even after adjusting for bad grammar, but what you're describing is adjusting the limit screws which has no effect on the indexing of the gears.