Fibonacci, the nickname given the great medieval mathematician Leonardo of Pisa, is connected in most of our minds with the Fibonacci sequence. Spreadsheets make wonderful tools for creating such sequences. This one is amazingly simple. Just select a cell, any cell and write a formula in that cell that adds together the two cells above it. Now copy that cell down the spreadsheet and seed it with 1 in the first cell. The Fibonacci sequence is a pattern that this action shows very well. This sequence has surprising attributes, and we explore some of them as well.