I believe that I am the only thing that really exists. I think that my friends and people I meet are versions of myself if I had taken a different path in life. I could be anyone and I can understand even the most ridiculous of ideas. It seems like a negative view but I am convinced that everyone or everything I encounter is to benefit me in some way. I don't believe in good or bad. Nor emotions or science. Just nature. I was created and all I am here to do is survive as long as possible. Period. No silly questions about the meaning of life or what is my purpose or am I a good person. Life isn't a gift it was just something that was possible and eventually happened. I think people like to lie to themselves to forget the fact that they are basically useless. I apologize for making this sound negative and too long. I guess my question is how can anyone prove to me that they really exist?
Your question reminds me a little of the story Bertrand Russell told about the philosopher who claimed that solipsism -- the view that only you exist or anyway that there is no reason to believe anyone else exists -- was obviously the correct position and she couldn't understand why everyone else didn't agree with her! But there does seem to be a sense in which you cannot prove that anyone other than you exists. Actually, in that sense, it also seems that you can't prove that you existed in the past or will exist in the future. So you if you have standards this high, then the most you know is the content of your current experience, though even this may be saying too much.