Abandoning the inner peace and joy in pursuit of the outside pleasures is a life lived under duality. Actions driven by ego rather than selflessness or love are actions performed under duality.
We live our lives pursuing ephemeral outside pleasures and trying to avoid pains, all the time ignoring the vast treasures of peace, bliss, joy, and love lying inside us. We are really, as they say, exchanging jewels for the glass. We are giving away this precious life for petty achievements, badges and pennies. The remorse will be tremendous when we lie down on our death bed.