Strange Cell Behavior

I have a spreadsheet on which I think I changed a setting accidentally. I can select any cell with my mouse without issue, but when I press any of the arrow keys on my Keyboard to scroll through cells (usually changing which cell is selected) it does not change the cell selection. Instead it moves the view around while keeping the same cell selected. It's almost like the cell that's selected is fixed and you can move the view around that cell. Any one have any ideas on what this setting may be?