No simple combination of atoms can teach anyone anything. Chemicals (just like meditation, conversation, diet, traveling, physical activity, etc.) can only create conditions for one to teach oneself and/or others.
In mammalian brains there are circuits of neurons that fire together at certain frequencies.
Imagine that a large group of people is told to start clapping. Each individual will initially clap at his own frequency, but very quickly the entire group will synchronize. The same effectively happens with neural circuits - neurons synchronize their activation rates and begin to fire together. The same happens in the society - protesters can form mobs that will self-synchronize without any leadership.
Now imagine one person in the group deliberately decides to clap at a different frequency. Synchronous clapping can easily be disrupted that way.
This is how hallucinogens work - by reducing the normal rate of activation of certain neurons they disrupt the established oscillation rhythms, throwing neural circuits into the state of partial disarray or even complete chaos ( known as "breakthrough" ), depending on the dose. Old, entrenched beliefs, ideas, perceptions can wobble and break down during this period of self-induced insanity. DMT (smoked or oral) with harmalas seems to be more useful than just smoked DMT because the experience is slower, longer and subjectively deeper.
Once the psychedelic wears off, the neurons will eventually find new ways to self-synchronize and oscillate together again. During this time ( known as "reintegration" ) one can recall memories, form new ideas, connect the dots differently, and answer difficult questions that one could not answer - or even ask - before.
One can only reinterpret the knowledge that one already has. Therefore, psychedelic experiences are the most useful in adulthood - late enough to build on enough prior knowledge, but early enough so that the people you love can still hear your words.