I don't know...
"Aptitude" ecompasses attitudes that go beyond getting the correct answer on a test.
I've always been led to believe that it was necessary for fighter pilots to be aggressively competitive in order to survive. Dubya doesn't impress me as having that type of personality. He's more laid-back, easy-going, wise-cracking, etc. He just seems to lack the focused intensity to go head-to-head with a Mig. Perhaps it was simply better for everybody if he just did his part in the reserves.
His flight instructor seems to have a different view of him than what we see from modern media. (Of course he is older now and has to show that laid back attitude...but then again...pilots have to be somewhat laidback and not panic...so who knows.)
This from a writing posted by ravingnutter in post 13 of this thread:
Retired Col. Maury Udell, who trained Bush to fly the F-102, has no doubt his pupil was willing to go to Vietnam. Udell agreed that Bush was too inexperienced for Palace Alert, but he said the young man did become a good fighter pilot. "George got really good in air-to-air combat," he said.
Udell, now a 270-pound judo expert who describes himself as a "war-type guy," said Bush had an extraordinary memory and ability to process information. From Udell's perspective, Bush's ability to overcome his aristocratic schooling at Phillips Academy in Andover, Mass., and Yale University and mix with the other guardsmen was more impressive. "It is OK to get a good education, but some of those people are a little off the wall," he said. "I just wanted to make sure that he was in it for real."
Udell said he spent six hours a day for six months training Bush. And that's not all. "We would go to the bar and play dead bug just like everybody else," he said. When someone yelled "dead bug" the pilots would hit the floor and stick their hands and feet up in the air. "The last guy to do that has to buy the next round," Udell said, laughing. "He was really good with folks," he said. But the young pilot did not take insults well: "You can't put him down too easily. He's really tough. He'll fight you."