Though you two might have gotten along really well for a time, you realized after a while that there's some sort of disconnect in your communication. At some level, your partner isn't entirely honest with you. This could be a major pattern of willful dishonesty, but it's more likely to be as minor and intangible as them holding a part of themselves back due to insecurity or past experiences -- and then you followed suit, because you felt vulnerable and self-protective when you picked up on this strange vibe.
Of course, when we're courting a lover and falling in love, it's perfectly natural to put our best face forward -- but doing so hides that whole other side of ourselves that comes out later, the side that isn't so kind and smart and well-thought-out. And if we've been in troubled relationships in the past, in which we learned to keep parts of ourselves secret as a method of self-protection, it's hard to relearn to live and love openly. But the point of a good relationship is to be ourselves, warts and all. You could have gotten involved with each other before you really knew each other, so your expressions of affection might have been less than sincere. And it's very possible that your partner has a confusing effect on you, making it hard for you to think clearly when you're together. The lesson of this aspect is for both of you to be yourselves and communicate as honestly as you can -- even when it's uncomfortable to do so.