I came across a comment in an Autism group several years ago and after reading it I had epiphany; I think it may apply here.
"So as an Aspie besides misreading cues, I also probably send off cues of being disinterested when I am actually interested. The more interested I am the more I will probably shut down. So who knows how many guys might be attracted to me but think I could care less about them."
In expanse of that, when interested...excited, stressed or what have you part of my brain just shuts down. I can only deal with what is in front of me. I, like you, maybe had a thought that I would ask something, but it'd completely fly out of my head while I was only able to process what was happening in the moment. It's like a brain glitch for me
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"Inside the heart of each and every one of us there is a longing to be understood by someone who really cares. When a person is understood, he or she can put up with almost anything in the world."