Staying in insert mode all the time is not ideal because you aren't usually inserting text all the time.
Since a large part of editing a text file is manipulating the text that is already there, most of what makes vim powerful hangs out in the other modes. In "normal" mode, you can type out two or three keys and quickly communicate not only where you want the cursor to begin editing, but also how much text you want to replace. There are a endless number of these short little sentences you can communicate to vim quickly about where and what you intend to edit.
This kind of complexity can be intimidating to a new vim user, especially if you go looking for a vim cheatsheet and find that keyboard layout that shows what each key does in each mode. YOU DON'T NEED TO KNOW THAT. At least, not yet. Just install the vimtutor package, repeat it every once in a while, and internalize the basics. Learn the things that are useful to you. Most vim questions are wildly googlable. Type in ":help", and read the description of how the command and navigation works. Then use it whenever you can't remember how every other command works.
Since a large part of editing a text file is manipulating the text that is already there, most of what makes vim powerful hangs out in the other modes. In "normal" mode, you can type out two or three keys and quickly communicate not only where you want the cursor to begin editing, but also how much text you want to replace. There are a endless number of these short little sentences you can communicate to vim quickly about where and what you intend to edit.
This kind of complexity can be intimidating to a new vim user, especially if you go looking for a vim cheatsheet and find that keyboard layout that shows what each key does in each mode. YOU DON'T NEED TO KNOW THAT. At least, not yet. Just install the vimtutor package, repeat it every once in a while, and internalize the basics. Learn the things that are useful to you. Most vim questions are wildly googlable. Type in ":help", and read the description of how the command and navigation works. Then use it whenever you can't remember how every other command works.