The universe is the reality, the 'totality', and our brain (thought) acts very much like a radio which 'tunes' a specific, very limited, 'channel' of this reality to make it 'my' world ... a very personal, narrow, limited world among so many other possibilities (channels) ... and each brain tunes its own limited world, its own limited 'perspective' of the universe, its own 'reality' ... and the personal channel we choose is the music we hear, the world we live in ... and each person lives in a different personal world he creates (or 'tunes') with his own brain ... and the number of 'channels' in the universe are infinite ... we chose to 'tune' one particular channel ...
Well not exactly a 'choice' in fact, as the radio was 'preset' at our birth ...
I would say the challenge of life is to learn to use the radio 'tuner' to change the channels ... or even at times set the radio 'off' and enjoy the silence

We are not the radio ... we are what hears the music ... or what enjoys the silence ...