Is the brain's "embarrassment" architecture single register in working memory?

At various points in my life I am plagued by what could be described as persistent unwanted thoughts. Basically something comes to mind, and is difficult to dislodge maybe for an hour or so, but sometimes much longer. I have strategies I like to use to deal with this, such as to actively get up and do something else to trigger a frame change.

A similar recollection-of-cringe-worthy incident occurred just now, but something slightly unique took place which I thought I would throw out for discussions.
So while daydreaming just before, I recalled an embarrassing cringe-worthy incident (see memory 1 description below) that happened many years ago. I had been reading a passage about Hare Krishnas soliciting for money at airports and it had reminded me of this previous embarrassing experience.
"...these Krishna members were arrested for soliciting without a license when they pressured Chrismas shoppers for donations after first pushing candy canes on them" - ("Influence", Cialdini, R, 1984)
The thought was quite distracting and strong, and as this is one of the ones that can be quite persistent I had a "here it goes again moment" expecting that it might put a downer on my whole afternoon.

However as I looked up, I noticed an upturned bed frame in the room which resembled fence posts, and that reminded me of a second cringe-worthy memory, the fence incident below (memory 2).

As I had been thinking about the process of "thinking about" and what triggers memories, I thought that was fairly interesting and was going to make a note of the association, but as I did so I realized that I could no longer remember which particular event was the original memory. That is I had dislodged the recollection of my guilt and embarrassment with the tourist in favour of the horror of the kids legs agony.

In order to recall memory 1 back, it was necessary to look back at the passage I was reading, to see the association with the soliciting Krishnasm, and trigger the tourist memory directly.

It seemed to me that the second cringe-worthy memory had "dislodged" the first cringe-worthy memory from my current "working memory". This is interesting to me, from a cognitive point of view that I might have only 1 "channel" for processing shame/guilt/embarrassment. And suggests some questions like can be completely occupied. (Can you saturate your shame channel, can you over saturate it?)

Anyway, this reminded me of Richard Feynman talking about "ways of thinking" - In it he describes some tricks that he had learned, but actually provide an interesting insight on how there are various internal strategies for cognitive behaviours

Its from his anecdote, he describes how he is using his "verbal" channel to processing the counting activity (by silently "mind counting" to 60 seconds etc), and that his colleague was using an alternative strategy, and using a visual strategy (he imagined a stopwatch ticking, to estimate periods of time.

But my experience suggests, that certainly in my mind, that my "embarrassment" facility maybe a fairly discrete process, given that it can be manipulated quite easily.

Here are the 2 events, for your voyeuristic pleasure

Cringe-worthy memory 1:

About 10 years ago I was waiting for a friend at a busy corner in Notting hill, London, and my friend was quite late. During this time I was approached a few times by beggars soliciting for money and this was becoming annoying. So I took to staring at the floor, and not making eye contact without anyone.

At some point a man approached and asked... "excuse me...?".

Just as this person spoke to me, my friend had arrived to witness the encounter.

Out of exasperation, I dismissed him with a curt "no sorry, not today..." assuming he was a beggar making a solicitation.

My friend looked at the guy, he looked back, and when I made eye contact it was clear, he was just a tourist, who was asking for directions.

And what was painfully clear that he knew what I had thought, and the look on his face indicated that he was very hurt by my actions.

I spluttered an apology, but the moment has stuck with me for years.

Cringe-worthy memory 2: 

The second memory one is of a video that I saw on youtube, it was pretty horrible video and I doubt I watched it more than once, but some of the physical features of the scene, such as the type of fence, the side-kicking action of the kid stuck with me, and trigger the memory afresh by many objects around.

So in this video (on youtube I think, but maybe some long lost video sharing site...) where some fairly horrible children are attempting to vandalise a concrete fence. (I recollect, but its an old memory)

One of the kids is side-kicking a concrete panel in the middle of the fence, and at some point the panel gives way.

The kids foot follows through with the broken panel, however the remaining panels above now fall to replace the lower missing panel space, which is now occupied by the kids lower leg and ankle. Effectively smashing and guillotining his leg. I have no doubt it resulted in serious injury, and what really makes it horrible, is that he would be stuck there for some time in horrible pain with his smashed foot trapped in the fence.