In auctex, to see the toc, we hit C-C =; there we have
a menu which goes like (r)escan (q)uit....
Does it make sense to have something similar in the agenda buffer when
C-c a a is hit? of course, 1 line in the buffer at least will be lost
to this new menu. I believe this would be useful for a beginner as I
distinctly remember trying to work out the single letter sequences to
do something. The only key I was sure was 'q' to quit.
And in a recent thread, Carsten told me about 'x' to bury/kill the
buffers.