We have no choice but to believe our perceptions and thoughts. Even doubt would be subjective and pure speculation. The problem is that few people seem aware of this simple truth and, so, live lives that testify to their delusion of objective truth and reality. Worse, they insist that 'others' (the humans they perceive, or at least believe they perceive, around them) have the same perceptions and reactions. If we are here for anything, it is indeed to enjoy the ride. I already took the 'out' option.