I have 2 columns, both with dates. I am trying to calculate the difference in
years between the two. I am using the formula =YEAR(C4)-YEAR(B4) This seems
to work well, my problem is that when I enter the formula for the first few
cells manually, then try to click and drag the formula down the entire
column, the results are just repeats of those first few cells I entered
manually.

Clicking on the new cells, the formula is correct, and if I click in the
formula bar then hit enter, the correct result then appears.

Is there a way to drag the formula all the way down the column without
having to manually click in every formula bar to have the correct result
appear?

11/3/1948 8/31/2005 57
6/29/1954 8/31/2005 51
3/11/1965 8/31/2005 40
10/1/1926 8/31/2005 79

If I click and drag that third column down, all I will get is
57,51,40,79,57,51,40,79 over and over.