Vanishing Twin

My first US, done at 5 weeks due to high hcg levels, showed twins. The Dr. told us about VTS and the 50% chance of one little egg sac vanishing. Despite that, we couldn't help but imagine a whole life ahead of us with our twins (which hubs just knew would be two boys), we even named them. And then, just like that, one was gone. I felt so disappointed, almost grief stricken, but everyone else (Dr., hubby, mom, bf) kept saying it was for the best and seemed to just brush it off. So I did too, and just focused on the positive - our one very healthy growing baby boy. Now he's here, and so strong and perfect in every way - I don't feel that something is missing, but I do occasionally think of the little one that didn't make it. I'm wondering if anyone else has had a similar experience, and most importantly, if this were to come up in the future, should I tell my son?