Think of a number...

For some reason, I actually know my national insurance number. You wouldn't think it's something worth remembering but it's actually just paid off.

Filing some old payslips away recently, I noticed the first two pairs of digits had been transposed. Further investigation showed that it was correct when I joined the company, mysteriously changed for nearly three years, then reverted back to the correct number.

No-one in payroll could shed any light on it, but a couple of frantic calls to Inland Revenue and NI ensured that everything has now been adjusted and I'm not subsidising a complete stranger's sick pay or pension fund.

So yes, it is sad that I've memorised my NI number and that I keep all of my payslips, but I'll bet it's something that most people would never think to check...