Do we really need to memorize the following color coding schemes? I think I'd have a hard enough time memorizing the Straight-Through color coding, let alone 2 other coding scheme's!

Straight-through
Same on both sides. Usually as follows:
(holding the connector upright
and looking from left to right):
White/Orange; Orange; White/
Green; Blue; White/Blue; Green;
White/Brown; Brown
Crossover:
Pins 1 and 3 and pins 2 and 6 are
switched. One end is configured as
above, but the other end is configured
as follows (holding the connector
upright and looking from left to
right): White/Green; Green; White/
Orange; Blue; White/Blue; Orange;
White/Brown; Brown
Rollover:
One side is completely opposite of
the other side. Typically, one end is
configured as a straight-through
cable and the other end is configured
as follows (holding the connector
upright and looking from left to
right): Brown; White/Brown; Green;
White/Blue; Blue; White/Orange;
Orange
Thanks!