Philosopher Robert Nozick proposed in one of his thought experiments an "experience machine". This machine is capable of giving you any experience you desire, and can simulate a fake reality that is more pleasurable than the real world. A user will have no recollection of the machine itself, and will be unable to distinguish the machine's experiences from reality. Once plugged into the machine, the user will have to live the rest of their life within the machine's reality.
Assume that the machine is perfect and cannot malfunction.