You can’t scroll through a Microsoft Excel spreadsheet forever.

Yes, folks, there is a limit to even what Excel can do. In the old version of Excel, you can only scroll over as far as column IV and you can only scroll down as far as row 65536. As of the 2007 version you can go as far as column XFD and row 1048576. If you need to fill up any more cells after that, you'll have to use "Sheet 2".