highlights of a meeting with my boss

Well, today may well have been the closest I have ever come to packing in a job with immediate effect. It was heated, it was unnecessary, and I lost my cool and threatened to walk out and not come back. I think the message got through though, and we eventually came to some kind of friendly conclusion and I returned to the calm of my office. Several of my colleagues could tell something had happened and came by to check on me and be supportive, and I have to say that made an amazing difference to my mood.
I'm aware I'm not explaining things very well; I'm just popping down thoughts as they come to me. So let me take you to 10am this morning, and a confrontation with my employer, whom I am refusing to name in this posting lest I thump the letters too hard and render my keyboard unusable.
It was so unnecessary.
He came barrelling in with a bug up his arse and barely said 'Hello' before launching into one of his diatribes. Apparently the leader of this week's course commented on me being 'uncooperative' and said that I might have got more from his teachings if I 'engaged more with the process' and this somehow caused embarrassment to my employer and caused upset to the course leader, which is hilarious bearing in mind he got paid a ridiculous amount of money per person for us being there. And his course, to be frank, was SHIT.
So I stood up for myself and told the truth about how pointless the whole thing was, and commented that maybe if people are so sensitive then they shouldn't be involved in management or consultancy in the first place, and managed to get a few other things off my chest that admittedly may have been best left unsaid, but he'd pushed the wrong buttons and I reacted. One thing I said was that I would seriously consider setting up my own training course and running my own seminars as I was far more experienced and qualified than any of the wasters I get sent to listen to, and could earn far more money than I am currently on by taking advantage of bosses like mine, the way these chancers seem to do with ease. That point was received particularly unwell.
But here's the thing - for the rest of the day, I've been thinking that it might actually be a good idea. Honestly, in my years of supermarket/filling station/caravan site management I've been sent on all sorts of these stupid things and I can't remember any one of them being anything close to useful. But there are loads of them available, and they're always well attended. Surely I can tap into that market and come up with something I can profit from?
Things got smoothed over today, but I don't know how many more of these run-ins I can take before I shove Gavin's head through a door.

RC 17-10-25