I think you only appreciate how important position is in poker when you have been playing for a long time. J10s may look pretty but from early and middle positions you are calling the blind without knowing what so many people ahead of you will be doing. What if they raise all-in? Or, what if just one person raises all-in? How sure would you be that your J10s will be the better hand?
Now if you are playing at a table where most players limp in round after round after round then you can probably play J10 from any position and see the flop for free. The whole point, I believe, is seeing the flop. What are the chances that you will see the flop if you just call J10s? If you have aggressive players to act after you well the chances are probably not so great since you will fold J10s in the face of any significant raise.
Position plays such a vital role because those who see what everyone else has already done before making a turn are at an advantage: they know who raised, who called, who folded and so they can surmise what cards players might have.
A great book on position play would be Dan Harrington's three volume set on Texas
Hold'em. I like Annie Duke's "decide to play great poker" as well.