You know you're the mother of a teenage son when you go into the bathroom the morning after he has gone back to boarding school and you find your spot cream is missing. This was the 18th time that I have sent him back to boarding school at the start of term and at this school it will be his last, as now 13, he will move to another in September.

I vividly remember the day I took him to boarding school for the first time, a few weeks short of his eighth birthday. The school had sent a list of the names and addresses of new parents and I was completely intimidated – they all had titles and/or addresses with no street numbers (for example, The Grange, South Newington, or The Manor, Pymble) – we were the only family with a bog-standard address. I spent so much time worrying about what I was going to wear and which lipstick to use that I forgot to pack his duvet, and we had to divert via Dickins & Jones in Richmond, London where I was so stressed that I almost bought one with a tog value of 4.5 until the sales assistant politely asked if I was moving to the Caribbean.