Maybe you have a memory as bad as Trump's, because if I spent two hours with someone one-on-one and then saw them just a few months later, I'd remember them.
A good executive has a staff that reminds him of these things. Even if it was a brief meeting, Trump should have been aware that he'd had a sit down with them before.
Either Trump was reminded and forgot, or he's too incompetent to set up a basic system like this.
"It's possible I have a picture with them because I have a picture with everybody. I don’t know them. I don’t know about them. I don’t know what they do."
To be fair, I doubt he tries to remember most people because they mean nothing to him. He will simultaneously say he doesn’t know someone, but that they are “good people,” or a “great guy.”