Map space key to go into insert mode

I am trying to map my space key to make the Vim go into insert mode from normal mode.

The reason I want to do this is because sometimes I forget that I'm in normal mode and start typing as if I'm in insert mode. When I press the space key in between or even in the start of the page, it moves down and something or the other types due to the possibility of a press a or i in what I just typed.

So to avoid this I want to map my space key to insert mode from normal mode as we press i to do so.

I tried the following:

map space :i
map <space> :i

But these doesnt seem to work.