This happened many years back. I have been using these reminder pads for a very, very long time. It proves very useful to me in jotting down important phone numbers, addresses , things to do and so on.
Once I was sitting in my friend's house along with a few others over tiffin and coffee. It is then that my friend told me about vade mecum and that it refers to the reminder pad that I always carry. So happened that the evening tiffin was idli and vadai.
So I said, Oh, I see. Now the vadai may come!! We all had a hearty laugh!
For anybody be it a businessman, student or whoever it is good to have one of these always.
It is really useful indeed as I have experienced myself.