The forever best answer...

I've taught first aid for a long time, in a fairly niche sector, and frankly, with all due modesty, I'm pretty darn good at what I do.
I don't teach first aid at work, or pediatric or village hall, I only teach outdoor first aid. And I'm also quite vocal that you should have extensive outdoor activity experience to be allowed to teach it. 

Probably the biggest call you're going to make is moving a casualty, no other course will teach you to do it, it's consequences writ large. I always ask the participants what factors applicable to where they work or play would make you make such a massive call. And I've heard a lot of justifications over the years; there's too much rockfall, the avalanche risk is too high, wild animals, no ambulances.
And then a couple of years ago I taught these watersports instructors for the first time, when asked the same question they all replied, in perfect unison... " the water is rising..." the perfect answer, it's the example I now always give.

12 strong passes today, a very very pleasing result.

Postscript:
This blip was nearly titled after the best quote of the day. Under a little pressure, and faced with an aggressive injured man, I suggested that perhaps a change of body language and voice tone, perhaps a little more caring approach, might work better. I got a slightly amused/exasperated reply " it's been a long day, I've given all the caring I've got to give". Very funny.