Doubting the Matrix. Is this a smart philosophy?

I have no explanation for why people are here and why the universe exists. I would rather not believe anything than believe something I know to be false, however. Basically, the only thing that living in this universe shows me is that I exist. I also believe that other humans like me exist, because that is the most probable explanation for my seeing them. There is no ultimate purpose to life, so people should do what they can in order to maximize their benefit from life, while minimizing harm to others.

It is not important to see everything there is to see, but make good use with what little time you have, and enjoy it. Don't spend an entire life earning money when there is so little time to use it, but live within the current economic system enough so that it does you no detriment, and helps you where it does not take too much effort. Live simply and fully. Beyond that, question everything. Take nothing for granted but accept things for which there is no other likely explanation (i.e. believe the statement "A group of humans live on Earth" rather than "I exist on earth, but other humans might just be complex AI (artificial intelligence) provided by a smart computer").

Figure out what you are doing on this planet, what you enjoy, and how you, personally, can get the most out of life. Then, develop a plan, and follow it. Leave enough time for thinking in the future so that you can check your progress along the way and slightly modify your plan where necessary. There is no given formula for a fulfilling life, and you yourself must figure out what to do in order to yield one.