Perspective, Mood, and Learning from Past Mistakes

I noticed that my ADHD boyfriend's perspective on almost anything is dependent on his mood.  This presents a problem since his mood is always changing drastically.  Here's a great example:

He recently purchased an $1800 musical instrument (with money he didn't really have by-the-way, it's ramen for him for awhile).  After receiving said instrument he was obsessed with fiddling with it hoping to "improve" it to some unreachable perfectionist state he had in his mind.  I told him he'd better stop fiddling with it and just accept it "as is" (which should have been OK since it was BRAND NEW off the factory line) or he'd end up breaking it, which of course, he did.  After he broke it he was in a very embarrassed state and was less hyper than usual and kept commenting that he should have just listened to me and that I always give such great advice etc. etc.  Well, after getting the instrument fixed by a professional, wouldn't you guess it.  He's back at fiddling with it again obsessed that what I consider to be a very normal sound for the instrument is actually an issue.  I said again to him, remember what happened last time?  You'd better stop fiddling with it.  He looked right at me with a hateful look and told me I was the most "negative" person he ever knew and that I need to "get a hold of myself".  Yup. 

What this looks like to me is that in his lowered-energy embarrassed state he was able to see what I was saying about leaving it alone, but as soon as his hyperactivity was spurred by his happiness over the repaired instrument, he couldn't see that what I was saying was smart and just felt annoyed by my perceived criticism.  I don't really know how to manage with a person whose rationale, thoughts, and decisions can change so drastically from one moment to the next and are seemingly dependent on a wildly fluctuating mood.

I also noticed that he has trouble learning from past mistakes because he has an almost pathological way of avoiding the negative feelings that come with failure.  I think this is true about many individuals with ADHD and I've even hypothesized that ADHD itself is actually a response or coping mechanism against dysphoria of any kind.  Without allowing themselves to feel "bad feelings" like disappointment, failure, sadness, impatience, frustration, seriousness etc. they can't learn from experiences that cause them in order to avoid them in the future.  Neuro-typical people learn from mistakes in that they avoid repeating them to avoid the negative feelings associated with the action.  My boyfriend only expresses "bad feelings" very briefly or in angry explosive rages.  I can see how ADHD symptoms themselves act as ways of avoiding feelings like sadness, disappointment etc. by using distraction and mania to divert them.  While this leads to a temporary relief it also leads to long-term issues with others and suppresses healthy expressions of emotion, and many other issues that the other 'symptoms' of ADHD cause.  It also explains why my boyfriend and many others with ADHD can not handle people "raining on their parade" so-to-speak.  For instance, my boyfriend gets very upset if I bring up ANYTHING that is unpleasant to him IN ANY WAY.  Which means, like many other ADHD couples, we can't work out our issues because I'm forbidden from even bringing them up!  Anything that could even be construed as critical or not 100% supportive is seen as "negative" and he then accuses me of being a horrible negative person (no one else I know thinks this, in fact I'm known to be one of the most positive people around).  He has a thing about not being able to be around "negative people" although his definition of negative and mine are QUITE different.  It just seems to me that individuals with ADHD try to avoid anything that isn't "very great feeling" which is why they avoid difficult tasks, arguments, chores, etc. and don't think it's BECAUSE of the ADHD as many speculate, I think it's because the ADHD itself is ACTUALLY a mechanism to avoid feeling anything but joyful or happy.  Whereas neuro-typical people can tolerate unpleasant-ness whether it is from difficult tasks, chores, important but difficult "talks" or arise from mistakes we've made.