I could not find anything online addressing this problem, which is surprising. The problem is that I find it very easy to accidentally insert stuff in Vim. I know I can undo by with 'u', but it still is quite annoying and frequent. Often, I enter a command like 'sp file.txt' without realizing that I haven't entered the ':' character yet (so I'm not yet on the command line). Unfortunately, there are several characters that take you to insert mode, including 's', 'a', 'i', 'o'. I'd rather have insert mode mapped to just one keybinding which is very deliberate, like shift-space. Can anyone point me to something that might have what I'm looking for? Thanks.