I think it depends on what you have selected.

If I put 1 in A1, select just A1 and drag that fill handle down, excel copies
it.

If I put 1 in A1 and 2 in A2, select A1:A2 and then drag down by the fill
handle, it fills the series.

Whenever I don't want excel to guess, I just rightclick and drag that fill
handle.

(It's a couple extra seconds, but I don't have to do it over and over!)

adarling wrote:

Until today, the default of my auto fill options was copy cells; in addition,
I never saw the auto fill box, ever. I've disabled the show paste and show
insert options so the box doesn't appear but it defaults to fill series and
adds a day to each date I drag and drop. Holding down the control key
overrides the fill series default but I'd like to go back to copy cells as
the default. Can it be done?

--

Dave Peterson