Activity

He’s certainly not saying that reality isn’t real.  He’s just saying that our perception of reality is a model put together in our brains based on the input from your senses.  We assume that our perception of reality is accurate, but we can sometimes see (in the case of optical illusions, for example) that it isn’t necessarily.  It’s just the best model our brains can come up with.  And your own existence as a conscious entity is another model your brain puts together from available data.

The people talking about meditation are saying basically the same thing, that your “mind”, or your perception of reality, is based upon ideas in your head which are in turn based upon the input from your senses.  Meditation is way of sitting quietly and sorting through all those conflicting perceptions.  Nothing more mysterious than that, really.