And because we don't know our preferences that well, we're susceptible to all of these influences from the external forces: the defaults, the particular options that are presented to us, and so on.
而正因为我们不清楚知道自己的喜好， 我们很容易受到各种外在因素的影响, 例如那个是预设的选择，提供给我们的是那几个选择，等等。