boolean isn't boolean?

why does a boolean value return a t or an f?

this goes against everything i know, i'm doing a php app(first time php
first time postgres, but i have extensive knowledge of oracle, sybase, and
more than a bit of MS SQL 6.5 n 7, plus extensive knowledge of c/c++ and
java and perl and elisp)

and  i have to check for $myarray[3] == 't' if i want to check for a true
value? why?

i just need to know that there was some actual logic behind this.

thanks,

marc britten