In most people, the liver actually metabolizes THC into a more psychoactive molecule, 11-hydroxy-THC. This metabolite is often thought to be more potent than the original THC. For this reason, a high from an edible is often stronger and more incapacitating than your average bong hit.
For some people, however, this may not be the case. It is speculated that many people have
genetic variations that may make them more or less efficient in breaking down drugs like THC. Some people may not always convert high levels of THC into its more active form.
These people may not experience the psychoactive effects of edibles. Inhaled consumption methods, like smoking and vaporization, are likely preferable to these people.