In the time of the Buddha, there were thought to be 6 senses: seeing, hearing, smelling, tasting, touching, and thinking. Although it seems a little strange to us to see thought lumped together with the other 6, there’s nothing special about 5 senses. For one thing, we actually have far more. We have a sense of hunger and a sense of balance. We even have a weak sense of echolocation like bats. Five is just the Conventional number. And when you get past the idea of thoughts as being some you do and rather just a function of the body, it seems less strange to lump it together with the other senses.
Before I was enlightened, when I was still just a spiritual seeker, I wondered: what is the allure of the 6 senses? What is their drawback? And how can I be free of them?
Then it occurred to me, the lure of the senses come from the pleasures that they bring. The drawback is that these pleasures are fleeting. It is therefore in their nature to bring suffering. The only way to be free of this suffering is to be free of desire from the pleasures that they bring.
Until I had seen for myself the lure, the drawback, and freedom from the 6 senses, I did not declare to the world of angels, gods, demons, spiritual seekers, priests, kings, and everyone else that I was awakened. But when I saw these things for myself, directly, only then did I declare my enlightenment.
And at that moment I understood: this freedom is unshakable. I will never be reborn. This is my last life.
-Pubbesambodha Sutta SN 35.13 (S iv 6)