I don't think it's really senility. I'm sure you've probably read an article by a news author about a technical subject that you know very well that just gets a lot of basic details/pov wrong as a whole. I'm pretty sure it's that, but with someone who has to take in 10x the amount of information on a daily basis. Combine that with an outsized, fragile ego and you get what you get from Trump. A vague understanding of things observed/read/viewed in passing combined with everything else.