How Mental is Judgemental?

Stereotype: A fixed, over generalized belief about a particular group or a class of people.
That's how my Psychology text book defined it. I swore by it until of course, I stumbled by the real deal.

Anyone with a tattoo is immediately categorized as 'wasted'.
If I love books, it's taken for granted that I have no wild side and that I am a nerd.
A girl who wears what she likes is someone with no values and God forbid if something were to happen to her, she definitely 'asked for it'.
Everyone with a beard and a moustache isn't a terrorist for God's sake.
Stereotyping doesn't just involve having a 'fixed, over generalized belief', it tends to draw some people away from the crowd and be looked down upon. It forms the thin line between what is considered normal and abnormal. It divides, and it rules.

Knowingly or unknowingly you're judging someone at every casual glance you cast. It's not always words that make your point. All that sniggering, raised eye brows, muffled laughs and pointing fingers qualifies too.
Congratulations, you have kept alive the tradition that came from God knows where and became an every day thing for everybody with the ability of forming an opinion.

When I write an article about a heartache you take it for granted that some boy trashed my heart and walked all over it.
Maybe that happened. Maybe not. Or maybe I'm just so good at what I do that I recreated a story from scratch and compelled you to confuse it with reality.
And at this precise moment, you're calling me a pompous rat.

If you ask me, unnecessary judgement and frail stereotyping is taking us down with much more force than dowry, casteism or global warming ever will.
Okay, maybe not the global warming but you know what I mean.

I want to be able to wear a pair of shorts and not be labelled 'easy'.
I want to be able to sport my glasses and not be called 'nerdy'.
I want to hang out with my guy friends till whenever I want and not fear being the 'girl who is always with boys- question her character'.
I want sarees to be as cool as tank tops.

I want to skip all the parts where prejudice gets the better of me. 

I'm genuinely sick of being cast into boxes according to my appearance and my behavior that changes every few months anyway. Aren't you?

How fair is it to chalk out someone's life span based on the hour long account that you've had of them?
How sensible is it to form an opinion about someone you don't know?
How stupid is it to carry on this tradition that's nothing but well, stupid?

How mental is judgemental, really?