Entering a dark room, someone mistakes a rope on the floor for a snake and is terrified. If they are told at that moment that what they see is just a rope and not a snake, their fear might abate but not disappear entirely, for they might still have doubts. If they turn on the light and see with their own eyes that it is indeed a rope, they will completely be rid of fear.

Likewise, we suffer from samsaric existence because we take dependently arising and transient things as real. Hearing about the Buddha's teaching on selflessness and knowing in theory that the origin of suffering is our attachment to a self, we nevertheless continue to suffer from afflictions. This suffering can only cease when we realise the nature of selflessness.

-- Khenpo Sherab Zangpo Rinpoche