And yes, I know that people are posting the video of Trump scurrying away from a bald eagle that snaps at him in his office, but that's unfair because it's very different from a semi-automatic weapon. For one thing, a bald eagle can fly. And for another, it's the symbol of our country, so Trump backing away was probably a sign of respect.
And keep in mind, it's not unreasonable in the slightest to think that Trump would run into the high school without a gun in the face of semi-automatic fire. That's because if he did, he'd be surrounded by half a dozen members of the Secret Service protecting him, with trained snipers shooting at the attacker.
Mind you, I do think that people are missing the bigger issue though when Trump said he'd have run into Stoneman Douglas High School without even a gun against a semi-automatic AR-15. Because the real question, and the only one with substantive meaning, is if he could single-handedly take down a plane full of armed terrorists like Harrison Ford did when president in Air Force One? Because that's really tough.
In the end, though, for all the ridicule, I do believe that Trump believes he actually would have run in to the high school AR-15 massacre without a weapon. Because that shows how nuts he is and that a con man is most successful when he convinces himself to believe his lies.