I just drink untill I can't think.
(just joking)
This is actually the best strategy, nothing that a good few gallons of beer can't solve
OP makes some really good points though, it's really important to take a step back at times and look at things from a holistic point of view, yes you could be much better off if you were god and you knew exactly what was going to happen, but you are not so you just have to do your best and if that leads to a profit then you can be very happy with that. This does not mean we should not be self critical and aim to learn and improve, it just means that it should stop short of chastising oneself.
Every individual has their own way to cope with their losses. Whether it may be by drinking beer, gambling, weeping, etc. all of us have their own unique sense of coping and if it works, then why stop? Due to our losses, it now creates this connotation wherein people should avoid doing their past mistakes that led to the failure of their investments.
Personally, I read investment books or walk on a Sunday afternoon in order to mitigate the pain caused by my failed investment strategies. Well like what they say, what does not kill you makes you stronger!
I just accept that I made a mistake, and move on. There is no point in dwelling on something that you cannot change. I accept the truth, learn from it, do better the next time. That is how you improve. If you keep regretting, you just lost time and focus, not very good in trading.
All of us need time in order to cope for our losses, especially when we're talking about large amounts of investments wasted due to negligence or being irresponsible. You may be right that everyone of us needs to move on but let time do the work in order for us to move-on completely.