Without strategy you can not know what is nuts or dro,how to play with dro or how to do right in the tournament.Fishes can not win sunday millions or something like that, because they do not know strategy, so the strategy will help you but it cant give you guarant that you will win. because its just poker, baby.
I don't think you need a specific strategy that you have to follow all the way to the end, but I do think you need to base your play in general around a strategy. It's a good tool to help you learn and find out what works best for you until you've played enough to come up with your own style of play.
Of course, you must have your strategy to the game differently in any way. produces little that strategy which is closer to your playstyle and that brings money.