This Is Why People Hate You: Habits
Your mom's right, hate is a strong word, but disliking people is easy. A foul mouth, cheering for the wrong team, or voting conservative can place you on someone's shitlist, but hating someone requires a deep-rooted disposition. To hate you, someone must be against the very foundation of your personality. No one detests you for your actions; no, they hate you for the things you do unintentionally. Everything you control is superficial, but below your Super Mario T-shirts and Family Guy quotes is a very dislikable gooey core. People judge you on what they can see, namely your habits, so we'll start there.
Cracking your Knuckles
Aside from the scream a man makes when his still-beating heart is ripped from his chest, knuckles cracking is the worst sound a human can produce. Cracking joints is like nose picking 2.0 because it disgusts and annoys strangers at the same time.
A lot of people say they have to, they're wrong. Cracking your knuckles has one purpose in society: it notifies all people within hearing distance that you're about to do something awesome. Crack your knuckles before you shred a guitar solo, slam-dunk, or save something from a fire, don't crack them in the back of your class or in a meeting unless you plan to do a back flip off the table. The next time you crack your obese little fingers and everyone looks back, you shouldn't apologize for bothering them-- you should apologize for disappointing them.
Nosebleeds are an evolutionary trait in humans to discover who's the biggest bitch. Before Star Wars references and thick-framed glasses, mankind had bloody noses. If someone messes with a thermostat you'll be hunched over a trashcan with a wad of toilet paper in fifteen minutes.
Luckily, everyone already knows you're the bitch, so don't worry. Unfortunately, the people who are kind enough to deal with all your other problems also have to cope with your bloody orifice for half the year. As if they have nothing better to do than wait on your nose's suicide attempt. Hell it wouldn't be a problem if you'd stop picking you nose. Which is another habit you should take care of.
But wasting peoples' time isn't enough to have them detest you, oh no. They don't like you because you're greedy. The wealthiest people waste what they have. So while the average person donates their excess blood, you, like some Emperor of Blood, would rather spill it in the sink or feel it pool in your hands on the way to the bathroom.