All of these do not take into account that people are often unaware or confused about thier own feelings and emotions. Also it is not as though most relationships are "planned". Sure that happens with all the classic first date, second date with a kiss, and after the third you're going steady if things have worked well. It's the standard to which we hold people often but is total male bovine fecal matter. Most relationships, particularly those with friends, rebounds, etc "just happen". People may have been intelectually against it but very often find themselves in it anyway. So just because someone says one thing and then acts another doesn't nessesarily make it a lie. Actually I found in talking to friends that more of them being more "on guard" with people who they "kinda liked" and ended up falling into a relationship with people who they disliked or didn't care about because they were not thinking about it and got caught up in a moment-not nessearily sexual. It might not hurt any less to be on the wrong end of it but it's sadley true that people are not very good at describing their own emotions even to themselves.
I wouldn't take it personally.