I have very good imagination. I often try to use it to predict all possible situations that can occur related to problems I am trying to solve. If I don't miss some important detail - I am usually correct at preparing for situations thanks to this.
My internal monologue is constant and omnipresent, especially if I am alone. It is usually critical of everyone and everything. It can even make me laugh at horrible but grotesque situations, but it allows me to appreciate things and situations that many people consider purely bad because they can't see any depth.
I am 27, not sure if I am autistic but I can relate to a lot of people are saying in their posts/comments about that. I don't like labeling myself because too often, I see people trying to put me in the nearest stereotype known to them.
Things from your post I can relate to:
My subconscious can solve entire problems for me but I can't force it or can miss it easily. It is a subtle feeling to me. Btw. - everything is a problem or a project to me.
My memory is horrible. The only way for me to think and not forget what are my conclusions is to write down, reread, correct, reread, reorganize written text which is better than my memory.
I do remember some events which made me learn something important.
Doing even 2 things at once is very frustrating to me.
I can figure out social interactions if I plan them. I am still learning and getting better at it but pain of social rejection is almost physical to me.
I have a great job now because I can do pretty much whatever I want as long as I can get it done, is text based, only mental, managers are very nice to me.
My previous jobs were horrible experiences. Just mountains of misery, not only for me. The feeling of powerlessness made these even worse.
I think that's your whole post answered to.