And the horse you rode in on

I'm a gamer, right?
I play a fair few games, right?
I rarely win but that's not the point of it, right?
Right?
Apparently I may have the wrong idea.

A regular Monsterpocalypse tournament that I'm a part of has had one of its players drop out because "people were too arrogant when they win".

Now, I'll admit that I may be a little excited when I win. One of the earliest I can remember is at Gencon Oz 2008 at the Warmachine Hardcore Tournament. I was playing against this lovely fellow from Newcastle and he had a list made up for him from the Tournament Organiser, Kel, whom he was also staying with.
I saw an opportunity. His Warcaster, Epic Nemo, was in the midst of a forest but had Line of Sight to my caster, Epic Irusk, so he used his ranged attack. I quickly asked if he agreed that I had LOS to him as well, to which he agreed that I did. So I cast "Artifice of Deviation" to let him pass the Rough Terrain and charged Epic Nemo, making two attacks against the old Codger, and secured myself a victory.
To which I jumped up and down excitedly, surprised that I actually won. I didn't expect to win at all that day, however on the first match I achieved an Assassination, which also contributed to my excitement as if I ever have a victory, it is not through assassination.
I did shake his hand and thanked him for a difficult game (he was on the right track to victory), but I felt bad afterward. It was rude of me to do what I did, regardless of whether I was praising myself or not. I certainly didn't say "Oh, you suck" etc, as that is certainly not something I would do.
Ironically, I won "Best Sportsman" at the event. I certainly didn't expect that. I've told the story many times of how Kel made a speech about how this is his favourite award, turned to me for a second or two and then said my name, and my immediate reaction of screaming the word "WHAT?!"
I was lucky enough to see the same fellow a few months later at Cancon and he didn't mind. I apologised anyway.

This is what made me happy. I play a good game. I won't win, but I'll make them work for that win (most of the time). Only on certain losses do I mull on it but that's still a rare event on its own.
In recent times, it has been a pendulum scenario, where the will try an assassination on my warcaster and fail, then I would do the same to them, failing as well and leaving myself exposed, securing them a victory.

But obviously this does not appear to be the case for our little absentee.
Now, he's an excitable little creature. I've had him jump up and yell something out at my monster when he has pulled out a really good move.
But he doesn't like to lose. Nobody likes to lose. However, there is always a point to be gracious about it: So that you may face them again without apprehension. Like making a good impression on a first date.
That is what we mostly do. Granted, Aaron is as boisterous as they come, but certainly not arrogant.

This shattered me. I looked back on it and thought "What have I done wrong? What was it that made this fellow abandon this group of gamers?"
I ask this because I was a regular opponent in the tournaments.
The only answer that came to me is from an old quote:

Some People will speak to certain others and say "I can't understand them, what is wrong with me?"
Others will speak to the same people and say "I can't understand them, what is wrong with them?"

I agree. As rude as it is, that quote probably does sit fairly accurately with him. There are still people in the world who take that viewpoint and will go to such lengths as to become zealous about this point.
Should it worry me about the future?
No.
In the eventuality where I face off against someone who believes in the same thing, I will continue to be gracious and try not to jump up and down in excitement if I win (I won't make any guarantees, honestly).