We close the moment by bringing to it preconceptions - expectations of others based on their past behavior, projections onto them of how we think they feel, beliefs about ourselves and what we are capable of. Such expectations and projections close the moment. They attach to it the shape of the past and prevent it from being new.
To live in an open moment one must travel lightly through life, without excess baggage that contains old wants and fears. With no baggage, we become part of the Infinite, part of the flow that is everpresent in which all things are possible and all things are new.