My therapist wants me to write to you as if you are alive. 
She wants me to tell you how much I love and appreciate you, tell you all the things I never got the chance to say. Only I never got the chance to tell you anything, nothing you were ever able to understand. You died in the dark, on August the second in the fourteenth week of your life. You died for no reason at all except that sometimes, infants just die. No father can be ready for that. I wasn’t. 
In truth, I told you so many things while you were here. None of them meant anything to you: to you my words were just warm noise. But it meant everything to me. You woke us up at all hours of the night, and if I’m honest, I never wanted to be the one to soothe you back to sleep. Now, I’d give anything for you at three in the morning. I wish I had never put you down.  
This is getting hard to write, so I’m just going to get to the point.
I read a book about us.
In this book a physicist says that our universe could be just one of many universes, that there could be infinite combinations of particles expressed in an infinite number of ways. Your daddy doesn’t understand it all, exactly. But if it’s true, then this, out of all the possible versions of my life, is one of the worst. And that makes me so happy because if that’s true, then it means that on the morning of August the third my girl woke up chubby and happy all across the multiverse.   
An infinite number of you learned to walk, and talk, and make us all laugh. An infinite number of you loved, and lost, and put your need for me into the past. An infinite number of you worked an infinite number of jobs and lived an infinite number of lives.  
I spend every night lost in the permutations of you, you-that-are-not-lost. 
This is the worst possible universe, but I still got fourteen weeks of you. There’s no way to qualify that quantity. I will always keep loving you and if you’re out there, and if we’re out there, our love for you will always be an infinite number.