How can a little boy 5 years younger be so influential? It's easy really. Everything Callum was interested in Kieron copied: from skateboarding aged 4 to Top Gear, WWE to the Simpsons, Sponge Bob to The Lost Prophets. If Callum did it, liked it, disliked it, Kieron followed suit. So Callum was always aware that he has a younger brother who hero-worships him and follows his example in everything. Kieron's shark and dinosaur fascination was started by his big brother as was his interest in cricket and pool. If Callum said it was cool then it was. No questions asked.
They were the best of friends when they were younger, Kieron accompanying Callum on visits to friends houses and football or cricket in the park. Kieron's friends mixing with Callum and Callum's friends looking out for Kieron whenever he tagged along. Kieron cheering Callum up if he had been told off and teasing him out of a bad mood.
During the last couple of years, Callum earned his pocket money by baby sitting during school holidays when I was at work and by the occasional school run if I couldn't get away from work in time. Gradually, they appeared to grow apart, but in reality, it was Kieron becoming more independent and increasing his social circle and own responsibilities. Also, Callum was allowed out later in the evenings, as befits a 15 year old, chasing girls.
So who do you turn to when your fan base has gone (as even some of Kieron's friends looked up to Callum), your irritating little brother no longer irritates and your perceived position in the family changes from older brother and middle child to little brother and youngest child (although I keep telling him he will always be older brother and middle child)?
No-one. Because the missing person is completely and irrevocably irreplaceable. He is Kieron.

