I've seen that some people are only nice or considerate with people who can provide them with things or help. When this is no longer the case then they are abandoned or ignored for other people that can provide help. Sometimes, people you consider family or friends can sometimes do this to you too. For example you really need someone's help but they don't want to help you because it's inconvenient for them. But this person will not hesitate to come to you for help whenever he/she needs it. Being a considerate person, you'll help with the problem and you do this because you consider that person family or a friend. The people i'm describing sometimes are totally unaware that they take advantage of other people and can sometimes be selfish as well as self-absorbed. To these people i say be more considerate of others and try to help your family or friends even when it is inconvenient for you because you never know when you'll need their help in the future.