Jumping to conclusions too much?

I don't know if it's just me or does everyone have this kinda uh... bad habit? Do you ever read or watch this new character appearing then they'll do something that irritates you like maybe example:
-steal the heart of the lead character
-be a bitch
-do something really bad etc.
When that happens, you'll decide that you'll hate them for life. Then something happens and you decided again that you don't hate them that much after all. In fact you might just start to really like this character. So, do you experience this? I know I always do.
I'll give you an example, Uee from After School. I hated her character in "You're Beautiful" cuz she's really bitchy and at some point i decided that i really hate her. Then i saw in this reality show "We got married" and i realize she's actually a sweet girl in life- respect the elders, kind and stuff.
It struck me, I was too fast to jump to conclusion, it was just a character she's trying to portray and i let that got the better judgement of me. That's why i said in the previous post about first impression. They gave me a bad first impression thats why i jumped into conclusion. I know it's bad but I can't help.
A few more examples: Suou "Tan Tan" from Saiunkoku Monogatari, Aoi Chan from Kaichou Wa Maid Sama, Agent Brody from Charmed....
Similarly, this also happens the other way round. (SNSD fans DON'T read) Jessica from Snsd. I thought it was cool that she's brought up in the states, she's pretty, her english is good. For a while (just a short while), i liked her. Then slowly i realize some things that made me eventually uh... hate her. Her voice is so fake, her personality like a spoilt brat and bitchy.(i knew this from watching reality shows again) One can really see the true nature in a person, even if it's for the sake of the TV, they're original character can't be fake and you usually find the truth there. The Kardashians, Jersey Shore even Giuliana and Bill, they can fake it for the show but you see their real self and BTW I reaaally HATE the Kardashians, they're attention whores and will do almost anything to attract attention (Kim's divorce).
Just a suggestion, the next time you were to decide whether you like the celeb? Watch reality show.