The first few birthdays in life are a celebration; more than that, even: praising fortune that the fragile first steps have been made without significant injury, disability or worse. From age three or four, a child will excitedly count up quarter years, half years, full years towards the next number, the next marker of respect and standing. Birthdays at this stage are about eating all the cake, getting all the attention, having all the presents. Then it's school-time, increasing age and perceived quickening of years marking out just as inexorably progress up the career ladder of education. Junior, primary, secondary, GCSEs.
Sixteen brings the first legal landmark, although it rarely has a significant effect on actions and lifestyle. Seventeen means learning to drive for hundreds of thousands of teenagers; eighteen marks a concept of adulthood. By nineteen one becomes aware that being "grown up" changes very little in terms of wisdom, knowledge and so forth, but at least it feels a step above being "newly qualified" in adult society. Twenty mainly represents an ending – the end of being a teenager – and twenty-one is the final big celebration. I suppose logic dictates – and experience has shown – that turning twenty-two is like turning nineteen: being "adult plus a year"; experienced; self-assured (in theory).
This brings us to 23. My first birthday post-education and the first one, really, to mean so little. The mathematics conspire to emphasise the insignificance – what difference is a year in 23? This is where the counting stops, at least until 30. But there we are, that happened to me during the week. In the words of Mr E. Izzard, "Thank you three people".