Mind can accept any boundary anywhere. But the reality is that, by its very nature, existence cannot have any boundary, because what will be beyond the boundary? - again another sky.
That's why I am saying skies upon skies are available for your flight. Don't be content easily. Those who remain content easily remain small: small are their joys, small are their ecstasies, small are their silences, small is their being. But there is no need! This smallness is your own imposition upon your freedom, upon your unlimited possibilities, upon your unlimited potential.