I can remember my bank account number and sort code for my main account, and my NI number, which is good because I think I've lost the card again. I even remember the PIN occasionally.

I also know all the phone numbers my mother has ever had except the one she has now. This is very annoying. Her mobile phone number is too much like Andrew's for me to bother remembering his with any degree of assurance that I won't ring my mother by mistake. I therefore have every phone number I've ever been given written down in my diary.