The other day I actually read the ASCII table. Seems odd as I've dealt with this for probably more that seven years but I've never really looked at the special characters. I remember when I started programming with QBasic/Visual Basic I first looked at the table - I ignored the non-printable characters as they looked too complicated. And for some reason I've never really looked at them again.
In my last job there were a number of ASCII protocols using STX and ETX but even then I never looked at anything outside of tab and carriage return (don't get me started on this character...). So yeah it's a bit of a surprise and now I plan to make better use (or ignore) these characters in my future code.