I hate using the mouse. It may be good for drawing, but when I’m trying to write or calculate something, I find that switching back and forth between the keyboard and the mouse wastes a tremendous amount of time.
So, I encourage you to teach yourself the keystroke combinations that will make working in Excel much faster and easier.
Many books and websites publish these keystroke combinations, but one that I found particularly helpful is this link.
Also, I found this article by Bill Jelen (one of the leading authors on all things excel) to be very useful. This article is short and sweet. You might also want to visit his website at MrExcel.com, though I get dizzy with all the different links and info he offers there.