Can Someone Please Explain This, Cause I'm Completely Clueless On It!

Why is it that people (myself included) so often avoid the "obvious" and probably right thing, and instead go knowingly after the harder to obtain alternative? Maybe it's because we fear that the "obvious" choice means it's the less desirable, that the harder to obtain choice has to be the better decision. Maybe we fear that by chosing the obious, we aren't challenging ourselves enough or we are just taking the easy way out? Or maybe we spend our life constantly wondering what will happen if we're with one person, what if someone better comes along? Here, allow me to demonstrate my point:

Boy likes girl. Girl likes boy. Girl is 100% aware of the fact that boy likes her, so in this situation, girl has a few popular options:

A. Girl can like boy back and can start dating him. (dating him, not neccesarily as in some serious, I wanna spend the rest of my life with you & have your babies way, but nice casual dating)

B. Girl can go out of her way to find someone better (at least at the moment) to date.

C. Girl can hang out with boy and lead him to believe that they could be together but secretly think that he isn't "Good enough" for her.

D. Girl will date boy.... but only till something better comes along.

I'm so confused. I don't get it. Maybe we all need to step back and appreciate the obvious. Realize that sometimes the obvious (the "safe" and secure decision) really is the thing that is right for us. It is the person, place or thing that we have been looking for all along & we haven't been able to find in all of the wrong places that we have been looking. Maybe a little "obvious" is just what we need in this life. xoxoxo