Are we close enough?

A close friend of mine said this once. At some point you are close enough with someone, next time you know that they are strangers to you. Is it because you know them too much that they show you a different side of themselves that makes you disappointed upon them? If I may say, I don't even know how someone are close enough to me or not. How you define your closeness to anyone? Relationship between people is just so weird. You thought that you are closed enough to someone that you had share everything on your thought to them, you give hand when its needed, you give attention more than you gave to anyone else, yet sometimes you don't get any feedback from them then you feel somewhat useless. Other time you might even get attention and trust from someone that you don't even consider close enough to them because you only act casual to them but then they are very kind to you. How am I suppose to recognize people? After all, quality over quantity means better isn't it? You cannot push someone's feeling to have somewhat a chemistry or relationship. It really depend on how you feel when you connected towards them. I assume that if you have shown your vulnerability, share your secret and deepest thought, give lots of attention, and do not even hesitate to ask help from someone you may feel comfortable with them and you think they are close enough to you but I guess it is not what everyone else may think. How would you feel if you are not even recognize as "close" to someone although you have given everything for them and that they also said "that" to you but then they said they don't have any close one? I feel like slammed in my face. Maybe that I expect too much. Well in any relationship with people I think we just have to consider everyone as a casual friend, so that you won't regret later if you feel deeply involved with them. I won't be regret anymore and I have the right to refuse and make up my own mind. To be independent is good enough but I think you have to know other condition when you ask help from them, don't be too bothersome if you don't want others think bad about you. We have our own ego to show our existence yet we have to control it unless people think we are too selfish. Kindness from people have its limit and you don't want to take it for granted everything, sometimes you might want to pay back to them or simply pay it forward to receive more kindness from someone that we don't even consider and thus showing that we are "aware" and care toward others.