That's like asking "Why doesn't it hurt when a tick latches onto your leg and starts sucking blood?" They've been designed (evolved) for a purpose. Pulling a

That's like asking "Why doesn't it hurt when a tick latches onto your leg and starts sucking blood?" They've been designed (evolved) for a purpose. Pulling a lever/pushing a button should get boring. Slots are designed to not be boring while they bleed you dry.