Because long distance relationships work can be fun- only if you have no other choice. :))
I never chose (directly) to be in a long distance relationship in the first place. It's just that I chose to study in a school far away from my comfort zone- my home, family, friends, and him. That's how our long distance relationship started. I spent five years in college away from him thus hindering me to see him everyday, hug and kiss him, be with him,etc. I only get to be with him during semestral breaks, christmas breaks, and summer vacation. All these breaks were not even more than two weeks! That is why I even joke around that although we've been in a relationship for seven years, if I am to count the days that we've spent together, I doubt if it would reach more than 365 days! That's the sad part of it though.
My point: Going for a long distance relationship may not be really a willful choice. Most of the time, it is a situation you have no choice but to be in to. I don't think couples who are truly, madly, and deeply in love will consciously choose to be away from each other most of the time. It is just that there are really things that you do not or cannot control. There are just moments when you can actually relate to the lyrics 'we have the right love at the wrong time'.
So that, as what I've said earlier, long distance relationships can be caused by the situation you are in but by all means, you have the choice to go out of that situation. Love is not a mere feeling. Love is a choice. It always is and it always will be. So before you choose to be in this kind of relationship, make sure that both of you are willing to go through it. Because I tell you, no matter how much loyalty, honesty, trust, prayers, and all the virtues in this world you put into your relationship, if either one of you is just not willing, it will NEVER work.