I compare this reality often with the reality I experience when I have a lucid dream.
I'm aware that I'm the only "real" person in that dream, though the other characters in my dream always try to convince me that they are as real as I.
When my friends/relatives appear in my dream, I know they are not real in my dream, but they have their own life (and their own reality) outside my dream.
I know that I exist, but I cannot know whether other people exist on the same level as I, because I can only experience things through my own body (I cannot feel what another person feels).
Considering this reality as a subjective reality doesn't exclude that the others cannot have their own reality.
PS. If there exists an objective reality, it will always be impossible to "see" this reality as it is, because we experience everything through our own body senses. What we call reality is per definition only a personal (subjective) perception of reality.