If only my older brother would give me bitcoin in 2009-2010 - I would be the happiest now! 
In general, it's very nice - I did this for my son when he was born 3 years ago, although I bought not bitcoin but etherium and not for $100 but for $500. Now they are worth much more. I confess I had a few moments when I wanted to sell them at a "good" rate, but then I caught myself in time and remembered that they were "not mine." Let the guy grow up and decide what to do with them. Who knows - maybe he will already be a millionaire by then?
In general, it's very nice - I did this for my son when he was born 3 years ago, although I bought not bitcoin but etherium and not for $100 but for $500. Now they are worth much more. I confess I had a few moments when I wanted to sell them at a "good" rate, but then I caught myself in time and remembered that they were "not mine." Let the guy grow up and decide what to do with them. Who knows - maybe he will already be a millionaire by then?