Afortunadamente means "fortunately" or "luckily." While it might seem like a common word, its placement and meaning in this song make it particularly impactful.
In the context of the lyrics, Jorge Drexler uses it to express a deep sense of gratitude and relief: "Que el corazón no miente / Que afortunadamente" (That the heart doesn't lie / That fortunately...). It highlights the positive and reassuring feeling that comes from trusting one's emotions, making it a beautiful and memorable word in this heartfelt song.
This song is one long, happy love confession. Jorge Drexler literally says he sings just to tell this person how good they are for him: “Para contarte, canto” [To tell you, I sing]. He keeps repeating “Me haces bien” [You do me good], as if normal language is not enough, so he has to say it again and again. When he adds “Te quiero de mil modos” [I love you in a thousand ways] and “Te quiero sobre todo” [I love you above everything], it feels almost childlike and simple, but in a bold way. He is not hiding how obsessed he is.
The cutest part is the tiny image he uses to explain this feeling: “Basta ver el reflejo de tus ojos en los míos, como se lleva el frío” [It’s enough to see the reflection of your eyes in mine, how it takes the cold away]. That line is the whole mood of the song. Just looking into this person’s eyes is like warmth arriving and the cold disappearing. Then he trusts his own feelings: “para entender que el corazón no miente” [to understand that the heart does not lie]. There is no big drama here, just someone very sure that being with this person is good for him, and enjoying saying it out loud over and over, like a love mantra set to music.