Gently...if your DD is close to your SI join date, you are too close to ground zero to consider such a deep question.
I am 13 months out and just now in a position to start to ponder what love is.
It is normal to wonder if you have just been na´ve and stupid....afterall, our fWS made a grand fool of us. They took advantage of the love, trust and compassion we showed them. We were used. We kick ourselves for being so stupid and vulnerable.
Upon DD we still hold to this notion that our vows still mean something to our WS, that we are still in this together. It took me 2 months to come to grip with the reality that my wife chose to kill our marriage as we knew it...she just failed to tell me about it. It hurts like nothing I can describe...but you know that.
I am projecting a lot onto you....your post was but one sentence.
If I am off base I am sorry. I don't have the courage to go into the Just Found Out forum yet....I see too much false hope and optimism in too many of those posts. I see my foolish self as I was back then...thinking surviving infidelity is like helping your spouse fight cancer. It is soooo not like that at all. But I, like them, have no other point of reference with how to handle devastating news...so we try to adapt what we know to adultery.
It simply does not work.
God be with us all.