The sense that you've known each other for a lot longer than you really have encourages you to idealize your lover, to feel as if this relationship were fated to be. You look at them through rose-colored glasses, at least in the beginning, convincing yourself that this is The One -- that this relationship is the most beautiful and meaningful of your life. From the first time you met, you raved to your friends -- We have so much in common!
This is so amazing! But part of this feeling comes from the fact that you two were actually involved long ago -- not in this life, but in a past one. Your relationship was similarly afflicted back then. Then, as now, you took it much more seriously than it deserved, and your heart was broken by the web of lies and deceit that your lover spun around you. In this lifetime, they may not deliberately set out to deceive you, but they do so anyway, just by portraying an image of themselves that's not entirely correct. Yes, a part of each of you is beautiful, noble, loving and generous, but you're still human -- you have your selfish moments, your gloomy moods, your less than noble impulses. To be fully understood as a human being is a wonderful feeling, but it requires a lover who can handle the fact that you're not perfect. Are you two able to see each other that holistically? It's doubtful.