My family tradition is one of training, training and more training. Even if you live a philosophy that you ARE the magic, physical practice is part of that YOU. And few are born fully aware of how one fully uses all the gift from the gods. Magical tools...either natural or more formal ones, like wands and athames, created for magical use in Wicca, are simply tools to train the witch. Not to mention that there are many schools of magical training, numerology, runes, languages, the elements, symbols, etc., that are wonderful to know from a historical point of view or to simply expand one's knowledge of magic. It all adds up to becoming the ultimate magical tool.
As others say - tools are not really needed to work magic. If you can wake up one morning, decide that you are a witch, and begin working magic in your mind...all blessings to you. If one records one's successes and failures and one's records prove one's success is not wishful thinking or self delusion...then one is a truly gifted natural witch.
Most of us need to educate and exercise our magical muscles. One of these ways is by using tools, especially if you are trained from childhood in magical thinking because some magical principles are too complex for a younger mind. Not to mention we are tactile beings. One can be in love with one's mate without ever touching them, one can grieve without shedding a tear, one can have a theoretical knowledge of skydiving but no one would argue that knowledge and experience are not the same things. All these things are knowledge with different shades of understanding. Why would one want to limit one's education?
Another use for tools is that they keep one grounded. It is perfectly possible to do magic in one's head but few can do that for long periods of time without losing perspective. Then, there is the fact that most people do not have complete control over or even clear understanding of how one’s mind or emotions work. The result being that these things often lie to us. If I ask you to close your eyes for ten years and remember the color blue - you would have to be an extraordinarily remarkable person to open your eyes and not be surprised that your memory was slightly off the reality. However, if you were allowed to open your eyes to refresh the memory, the memory has a better chance of recording accurately.
This is the same if you type for years and suddenly do not have access to a keyboard. Ten years later your fingers and mind will remember how to type. The same about bike riding and roller skating. If you are the magic, that means the whole you, your body and physical practice, is an integral part of your magical ability.
I was taught to begin with tools using a philosophy of sympathetic magic. That like images attract like images, even those symbolic tools gathered in nature; stones, leaves, feathers, shells, flowers, herbs, barks, water, soil, salt - used with pictures, handwriting samples, mementos of those we work for. Then one can learn to do it without these things. Even still, I return to the tools occasionally to stay grounded,or to learn a new discipline just to expand my magical knowledge or for the shear joy of learning.