Because you like Jack Ryan in Clear and Present Danger

When the Sorting Hat touched Draco Malfoy's head, it placed him in Slytherin, a house that has turned out more dark wizards than any other. See them in Harry Potter Series.

What Ron Weasley lacks in motivation and book smarts, he makes up for in loyalty and street smarts. See them in Harry Potter Series.

Severus Snape is a misanthropic potions teacher with a vindictive streak. See them in Harry Potter Series.