Adore your Lady. When she feels valued, appreciate, respected & loved by you; She won't even consider looking to someone else to make her feel special... Most men are not smart enough to realise that the higher you raise your women, the less available she is for other men. When you break her down, you make her accessible to anyone she thinks will treat her better.
I think that the most heartbreaking thing I've learned in the past year or two is that things change and people change, and no matter how much you love or care about someone, there more than likely will come a time when the two of you will pretend not to know each other, and you'll pretend that every memory you've ever shared doesn't exist.