‘I am 43. I have a three-month-old and a three-year-old. Compared to historical norms it is slightly later to have children. If you take the average lifespan, what milestones will I be around for and what would I potentially miss if I were to live 10 years fewer as opposed to 10 years longer, and also will I have the functional capacity to be able to do the things when they have milestones?” ponders Dr Paddy Barrett.