If I'm actually a Boltzmann Brain, all my memories are a lie and I just exist for a picosecond, then Boltzmann Brains can experience subjective experiences, so

If I'm actually a Boltzmann Brain, all my memories are a lie and I just exist for a picosecond, then Boltzmann Brains can experience subjective experiences, so what? >This also means that 'cogito ergo sum' is too strong of a statement. Just saying "something exists" (as in, "why there's something rather than nothing") seems sufficient. How do you know that something exists?