Everyone has to get relatively equal value from you in one way or another. Or even better put, people must get more value from you than the resources they are putting in. When people are young I think many (most?) people don’t consider this fact, but as people come to terms with it many people resent it.
When a person shows interest in you, for whatever reason, there is an expectation that will emerge from them. They will, at some point, be looking for; sex, money, validation, entertainment, connections, or another resource that they can extract or if you. There is no motivation that is just the goodness of someones heart … or if it is, it is just seeking validation (“see, I am a good person and I am using you to feel good about myself.”)
I’m not cynical. This isn’t a bad thing. It is just a fact of reality that some people resist, or they are naive. We all trade. I seek many things from my wife and she seeks many things from me. We are happy to trade these resources with each other in abundance. I have friends, employees, acquaintances and a myriad of other relationships that trade value with one another. I think this is a beautiful thing. We are social creatures and we have many needs, trading with one another facilitates wonderful interactions and relationships where everyone gets what they want.
I think it is important for people to truly understand the value someone else sees in you, otherwise someone is going to try to manipulate you for it. This is especially true for women. Since women hold value for men purely by their existence (the fact that men crave their body for sex) … men will often act selfless in their interest to women. Of course, this will often be the case if they want to court them (without being too forward). It’s pretty complex. If someone is constantly looking for the angle the person showing interest has, they will find themselves less able to be manipulated.
An interesting thing to comment on in regards to this are women who keep around guys who like them (or as a friend of mine called them, beta male orbiters). These women kind of accept the fact that everyone has to get equal value, but resist it by not letting these guys actually get anything from them. They end up teasing value in front of these men by offering them a mild sort of distant friendship and every so often let them have hopes of sex or a relationship. Of course, they have no plans to actually give anything of value to this guy. It is just a plan (often subconscious) to extract resources without having to offer value.
I think it is a horrible idea for anyone to maintain a relationship that they aren’t extracting extra value for. If a friend takes more work than he offers value, drop him. If you have romantic interest in a girl, but she doesn’t share it … don’t be her friend. If parents are a pain in the ass and don’t bring anything of value to the table, stop associating with them. If you don’t do this, you end up attracting people who desire to extract resources from people without offering value.