What does it mean to be a friend?

I thought - there is never a good enough reason to lie to a friend, either overtly or by omission, in an effort to protect their feelings!

I thought - being a friend meant that you sort stuff out, that nothing gets left unsaid.

I thought - when you value someone's friendship and company, that you tell them the things that they need to hear, even if they don't like it.

I thought - real friends don't make you feel like a fool when you find out what they really think.

I think I don't understand.