In the world of magic, fiction and reality, the amount of power you wield is almost always directly proportional with the time you've spent actively learning it.
Even if a novice were to cast a spell written and designed by a high priest, it would not be nearly as effective in his/her hands, simply because he/she doesn't have the proper alignment with the elements or energies involved. Being aligned with such energies takes time, and practice, though a natural affinity does boost your ability a little.
Not the point you could take down an experienced mage, though.
The author has done her homework, I'll give her that...even if the wand thing is bogus.
