By your logic, that you didn't own but used nevertheless: You don't know I asked those questions, you only know that your sense impressions have been triggered

By your logic, that you didn't own but used nevertheless: You don't know I asked those questions, you only know that your sense impressions have been triggered. Similarly my eyes sent some signals to my brain and after processing them I have concluded that you have replied to my comment. But wait! I don't really know you replied me, do I? Since my senses are unreliable and I don't have any other means to interact with reality but my senses, my mind is impotent to deal with reality. What else can I do but go through my life hallucinating and doubting myself or inventing fantasies to keep my sanity. ----- When you look at the moon (at the right time) you see circle. Then you can decide the moon is circular. Your senses are working just fine, so is your brain. It's your limited knowledge that leads you to wrong conclusions. As you observe and learn more, you integrate more and more concepts and you can eventually arrive to the point that moon is indeed a somewhat spherical object. Or you can conclude that your senses are lying to you and reality cannot be known. Then you'd never go further than "looks circular, but know knows, right?".