Thinking of this always gives me a little comfort:
I have two credit cards and a debit card. I use them so rarely that, if you showed me the numbers on any of them, I wouldn’t recognize them.
However, I have my 14-digit library card number memorized.
Life is good.
Gently Hew Stone 
I take it as a compliment that the librarians know me by name and remember my tastes.