Harry couldn't master Occlumency because he couldn't shut down emotion – he was hot-headed, ready to spring into action, unable to stop himself biting back. Draco, on the other hand, was well able to control himself when circumstances demanded it.
Also of note, while Harry's use of Occlumency in the books was negligible, he was nigh-effortlessly able to throw-off the Imperius Curse (both by Bartemius Crouch Junior-as-Alastor Moody, and by Tom Riddle), by willpower-alone.
Occlumency, Snape once told Harry, “seals the mind against magical intrusion and influence.” And Snape was a master of Occlumency, so he knew what he was talking about. But why was he so good at sealing his mind?
Snape is, by nature, a very secretive person. He likes to keep his private life and thoughts to himself. That is why he is so very good at Occlumency; he doesn't wear his heart on his sleeve like Harry, and he can control his emotions fairly well.
Voldemort Was The Most Accomplished Legilimens
Dumbledore and Snape both described Voldemort as the most accomplished Legilimens that there had ever been.
Voldemort intentionally made six Horcruxes, but when he used Avada Kedavra on Harry, he unintentionally created a seventh Horcrux. Instead of dying, Lily's love for Harry created a counter 'curse' known as Sacrificial Protection and saved Harry.
Occlumency
Draco shows himself to be a powerful Occlumens, capable of resisting even such a talented wizard as Snape. Occlumency takes an intense amount of mental willpower, and Draco shows himself to be a natural at it with only a few lessons from his aunt Bellatrix.
In 1996, Bellatrix Lestrange trained her nephew, Draco Malfoy in Occlumency so that he could keep his mission to kill Albus Dumbledore a secret. Draco became skilled enough to repel Snape's attempts at Legilimency.
He would always resent Harry for being James' son instead of his. Snape even said that he didn't want anyone to find out that he was protecting Lily's child, “especially Potter's son” (pg. 679 of Harry Potter and the Deathly Hallows) because of his hatred for James.
“Snape was a highly accomplished Occlumens,” said Lupin, his voice uncharacteristically harsh.
Occlumency (possibly): Though it was never confirmed, it was still implied that Narcissa was probably a skilful Occlumens, due to her ability to effectively lie to Voldemort himself, who was believed to be the most accomplished Legilimens of his time.
Formerly known as Tom Marvolo Riddle, Lord Voldemort was the most formidable evil wizard in the entire universe. Until Harry Potter, Voldemort's magical prowess was practically unmatched, and no one could stand a chance against him.
On 2 August 1995, Harry Potter unknowingly performed underage wandless magic in an alleyway in Little Whinging due to the presence of Dementors, with Harry speaking the incantation for the Wand-Lighting Charm aloud (Lumos) despite not holding his wand which he had dropped in the darkness, which instantly illuminated ...
Divination
Sybill Trelawney once described divination to her students as "the most difficult of all magical arts." Given that Hermione dropped the class and Harry Potter and Ron Weasley barely scraped by, she might have been right.
In some cases (the Malfoy family) blood traitors are a bad as Mudbloods. As other people said, it is also due to the Malfoys' arrogance, the feeling of self-importance and wealth. The Weasly family is also very poor, which may also lead to a dislike with the rich, pureblood families.
“Dumbledore didn't want to lose his wand at that point and Draco disarmed him. So that meant that the wand gave Draco its allegiance, even though Draco never knew it, even though Draco never touched it. “From that moment on, that wand gave its allegiance to Draco, and it wouldn't work as well for anyone but Draco.”
It turns out that instead of rejoining the Death Eaters, Draco was supposed to help Harry at the very last second by throwing him his wand to help him defeat Lord Voldemort.
Therefore, figuring out a spell that is Draco's favorite is hard and, in the movies, there is no defining moment that cements a spell as his favorite. Based on Harry Potter lore, and an article by The Healthy Journal, Draco's signature spell is a N.E.W.T standard spell, The Protean Charm.
It's never explicitly mentioned, but it's possible that Draco Malfoy can perform wandless magic. After spotting an invisible Harry in his compartment, Draco shuts the door and closes the blinds to block out sight so he can confront Harry.
When it comes to actual ability as a wizard, a case can certainly be made that Draco Malfoy is more talented than Harry. The only thing that Potter beats Draco at is his flying ability on a broomstick, but even then Draco pushes him all the way.
Narcissa Malfoy's Very Dangerous Lie
But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
Her sacrifice gave Harry the power of love, a protection spell sealed with the blood spilled by her death.
Though Harry encountered many opportunities that deemed Avada Kedavra necessary, it remains as one of the Unforgivable Curses Harry Potter never cast. For one, he viewed the spell as an immoral practice commonly used by users of the Dark Arts.