Everyone has a natural game, an alpha male of absurdly high value. Our society has trained us to bury our alpha male deep below levels of awkwardness and societal fear. Our goal as PuAs is to unlock that game, let our talent flow rapidly. It is dammed up behind societal rules, and we must destroy them.
Imagine your river of natural game trapped behind a giant brick wall of fear and whatever other bullshit excuse you make up. There might be a few cracks in it, depending on how good you are before studying PU. Maybe you've got a stream going. Whatever. PU completely destroys that barrier, your game flows out and you are in control of your environment, your alpha male presence is felt by all.
Canned routines are like your sledge hammer. Use it to break holes in your natural game, allow it to flow rapidly. Once your natural game picks up momentum, not only will the wall crumble away on its own, you will not need canned routines either.
Let it flow man, let it flow.