What breaks a friendship

I have learned in my adult life that most friendships that break are broken by one of a few things.

Someone lies/or someone tells the truth and it hurts the other person.

Sometimes someone can't stop taking advantage of someone else and eventually the person uses up all of the other person's grace and forgiveness.

People grow apart as their morals, ethics and values advance with age.

I've heard people say that eventually they got tired of someone else's emotional drain or drama queen antics but those seem less "forever".

But, talking with a friend yesterday we determined that out of all the things that can break a friendship beyond repair is abandoning someone in a crisis or blowing your cool because they are in over their head in life.

I don't know that that's always true for me because I can be pretty forgiving. But, I can think of a few people who bit off an issue in the heat of crisis that I've never trusted again. For every person like that though I have a well intentioned person that I have been able to let back in. Some of those people took longer to forgive than others but it usually happens.

And you know what? I have no idea what the difference between column a and column b is. Weird right? I mean you'd think with as many people as I've had kick me while I was down in my life I'd have figured out the line between the one's who got my Christian grace and the one's who got an Aries verbal firefight or the brick wall later at shared social events.

How about you? Are you forgiving or do you hold a grudge? What turns the tide for you in a friendship? How do you determine what is ok and what isn't when it comes to drama?