Halloween is an ancient Celtic festival that celebrates (or celebrated) the Lord of the Dead. During their festivals, they dressed in scary costumes and carved scary faces on turnips (and now pumpkins) to scare the evil demons away, and made huge bonfires where they burnt offerings to the pagan gods (like vegetables and children - nice mix, huh?)
Later, since the Pagans wouldn't stop their death celebrations, the Christian church changed the name to All Saints' day (a celebration of the Christian saints instead) and voilà! Now everyone's beliefs are combined and everyone is happy. Then from that was All Hollow's Eve, and so on and so forth until it was Halloween.
Now, little kids run around in princess costumes collecting candy from strangers and decorating their homes with death symbols.
...I'm sure that the princess costumes did a much better job at scaring the demons.
Person: Hey, what are you being for Halloween this year?
Other person: I'm gonna be a witch with freaky hair. What are you gonna be?
Person: Haha, I'm gonna be a dead cheerleader.
This has many meanings.
Some common ones are Less than three <3, a sideways heart <3 (normally meaning love), and a face <3.
The < is the eyes/eyebrows, in a.. well, happy position. Kinda. And the mouth, 3, is like an animal mouth. Kinda.
Such as :3, =3, ;3, and so on.
But basically, whether a heart or a happy face, the meaning usually comes out as love or happiness.
Ad more threes and exclamation marks to show that the emotion is more.
I <3 Kitties.
omgz! <333!! Thankyooo!
Less than three <3 and more than one >1