I can't quite say that I've had a proper first aid course, but the very first book I read at age 5 was a survivalist manual, and I still keep a free offline copy of the survivalist manual on all my devices.
I'm also a BMX flatland rider, so I've had more than the average person's share of injuries in my life and am pretty adept at tending to my own wounds and injuries.
So even without full first aid training, I know enough to make quick use of the limited supplies, while at worst I'd hope someone else might be around to call 911 or something.
Given the limited space, I more or less packed it to tend to busted knuckles or busted knees or whatever. Other things such as benadryl for allergies, pepto for upset belly, and BC powder for either headache or fever reduction.
I surely hope nobody ever needs to use this kit, but it's better to have it and not need it than to need it and not have it.