I think for many, it may seem terribly burdensome, tedious and pointless to talk about waiting years for a woman. It all depends on your perspective. If you are in need of a woman tonight, it is a pointless discussion. But if you are really looking at the big picture, that is, to love many women in your life, then it is just a logical conclusion that one need not waste an opportunity for the future.
The fact is that if you took a cross-section of the women you will find worthy of your effort, more than half of them will have a previous commitment to another person at the time you approach them. For some, a previous commitment won’t stop them from a liaison with you. (This is subject to your conscience and at your own risk.) Some will lie about that if they are interested enough in you. Some will tell you truthfully that they already are seeing someone.

If you are accepting of their current situation and can manage to maintain a friendship with her, then it is possible that you will someday have an opportunity, perhaps a day sooner than you think!
My experience is that the main thing is that you must have a way to reach her at a later date. Once you establish that, just contact her periodically, and let time work its wonders.