In any relationship – be it friendship, partnership, parents-children and so on – there are usually two extremes: the selfish and the unconditional love. Neither of them is good for everybody, but the worst is when they are mixed.
When a child is selfless and wants to help his or her parents, who make use of it. This way, that child will not have a life or goals, since as soon as he or she starts to focus on him- or herself, the parents always come up with something to do. It works the other way around, as well, when a child forces his or her selfish needs over the parents, but it is easier to solve with a firm partner.
As for partnerships, parasitic and yielding love can kill each other on the long run. One of them does everything for the other's sake, but it is never enough for him or her. It is not only exhausting, but it poisons the relationship from its core, since a selfish partner will never see the selfless one's problems, and he or she will blame the exhausted one for being negative or sad all the time. If neither of them gives up on the core of his or her personality, there is only one question left: when the relationship will end.
With friends, it is not that serious. There is not as much at stake as with family or a partner, they usually solve these problems ahead of time, and if they cannot, they make friends with like-minded people at a pretty young age. If we could apply this attitude in the other areas, as well, then our lives could be easier.