Hood was very good at lower command.
He began as a captain, quickly was made a colonel, and won brigade command right off the bat.
At Gaines Mill he took his brigade through Union lines which had proven impenetrable to previous attacks, over terrain which made an attack all but impossible. He forced the surrender of an entire Union regiment (4th New Jersey), and follow-on units capitalized on his breakthrough. It was the only Confederate victory during the Seven Days.
He then got a division, and was equally as good.
At Second Bull Run, his division hit harder than any of Longstreet's divisions. At Antietam, he inspired his men to die in a suicidal stand which nearly destroyed his command. During the Suffolk Campaign, he was Longstreet's #2 and performed admirably.
Things changed at Gettysburg.
He was in nominal command of two divisions on the second day, and failed to properly coordinate them. They took heavy losses and failed to take their objectives.
And Hood lost the use of his arm to a Union bullet.
And then Hood went to Richmond to heal. And became an instant celebrity. Here was a young man (he was only 32, despite the 60 year old playing him in the movie Gettysburg), actually from Kentucky but perceived to be a cowboy from Texas, a striking image (over 6 foot, impressive beard, apparently handsome, sad looking)...Richmond society built a legend around him.
And he believed it. He convinced himself he had a relationship with a flibbertigibbet, and probably a slut, in Richmond. He convinced himself that he was a great general, destined for higher things.
He made a friendship with Jefferson Davis and began to schmooze. Davis loved it when people sucked up to him.
Hood then went with the rest of Longstreet's corps to Chickamauga...and ****ed up again. And lost his leg.
Back to Richmond. Back to basking in false glory. Back to sucking up to the Prez. Back to deluding himself.