The Repeat command, executed with the dot or period key (.), is more useful than it first appears. Once learned, you will find yourself using it often.
|.||Repeat the last change|
|10.||Repeat the last change 10 times|
So then, for a very simple example, if you make a change to line 1 by typing i
IEsc, with the following result:
1 I made a mistake 2 made a mistake 3 made a mistake
Your cursor will be at position 1 of line 1, and all you need to do to fix the next two lines is press j. twice - that is, j to move down a line and . to repeat the last change, which was the addition of the
I. No need to jump back into Insert Mode twice to fix those lines.
It becomes much more powerful when used to repeat macros.