Bit of a catch 22. In order to learn to tolerate the less cognitively gifted, I'd need to spend a large amount of time in the company of someone commercially worthless enough to have become a teacher for a living.2 tips then:
Get some training (or help!) so you can address your weaknesses in both patience and in training.
Get some training on your recruitment problem, so you stop hiring stupid people who can’t be trained.
You’re welcome.
They're not stupid, just comparatively so. Anyone capable of learning to be as good as me is probably already earning twice what I do.