what makes a friend?

I was watching Dexter tonight. i know, all my references are to tv shows these days.  don't hold it against me.  but anyway, i was watching in the 3rd season(if anyone who reads this is familiar with the show, and i don't think you are) in which dexter, the lonesome sociopath, meets a friend.  he questions how far to trust a friend, how far does he go for this person and how far does this person go for him.

and to me, the questions were always so simple.  maybe it was the way i was raised, but i think part of it is just me.  i have this notion that everything i have is for the giving, that a true friend is the person who is eager to talk to you about anything, and will bend over backwards for you when you need something.  I've needed my friends to deal with me going crazy, and coming back again.  Family, of course, is there when you need them, and there when you don't.  that's a given to me. (and yes i know how lucky i am that i have them to take for granted)

who would i get up in the middle of the night for?  and would you do the same for me?  how does a friendship survive when the parties involved have different definitions of who they are to each other?  we each have our own value systems, our own upbringing, and our own self preservation.

::tangent::
i just looked up where the phrase bleeding heart liberal came from.  turns out it means someone who is excessively compassionate.  excessively compassionate?  how does one have sympathetic consciousness of others' distress together with a desire to alleviate it too much?  feeling sorry for someone, having pity, those are apparently synonyms of compassion.  but i disagree.  because pity and feeling sorry for someone have, in this day in this country, the implication that you feel you are better than someone.  but compassion?  com means with, and i don't think compassion means with passion.  not to me, at least.  to me it means that you are, in your own mind, sitting just next to this person feeling bad right along with them about what is happening.  it means you want to do something about it because you see that something needs to be done.  it means taking power with your sadness and turning them together into good.  so when i hear the term bleeding heart, and someone tries to make it a negative thing, it doesn't work.  because i just think, yeah.  that's me.

::end tangent::

it's just that i think that if i can feel that much emotion towards someone i don't know, other than they are a fellow human being, how can i not feel that for a friend?  and if i feel that strong connection toward my friends, how can it not be mutual?

so, dexter, what makes a friend?  trust?  respect? mere company? does a person have to have something in common with you to be a friend?  i've found it remarkable recently to realise the people i talk to the most i have the least in common with.  no similar music taste.  or work. no shared history.  no shared outlook on the world.  what do we have in common?  nothing.  what do we talk about?  well, i couldn't quite tell you sometimes.  but somehow, i've learned, all humans are connected.  once you find the point of entry, any person can be a friend.

so. making friends, i can do.  keeping them... i'm having a harder time with that.  and what do we do when the other person isn't living up to that friend code?  then what?

what ends a friendship?  how many of those secret rules must be broken, how many days of disappointment until you cross a person off the list?  i've crossed 3 people quite definitively off my list in the last 6 years.  does this make me more harsh with my list?  does this make me a bad person?