This song is about watching your children growing up, and realising that one day they will be faster, smarter, and have way more energy, and accepting that you will not see their whole life, and they will experience and achieve things after you are gone - which is sad - but because we love them we can celebrate their life in advance - and let them know how much we would have enjoyed sharing those things, and how proud we would be of the things they do in their lives.