Only the toughest and strongest girls can be good field hockey goalies. They are brave enough to let girls drive balls at over 90mph straight at them. Most people think that goalies are just one big wall of padding, but some pads have gaps in coverage that can result in extremely painful injuries if hit. Imagine getting hit with a ball going over 90mph, straight in your thigh or hip- that's what it's like to be a goalie. Balls often pop up, so goalies need to deal with shots to the arms, hips, and thighs.
Goalies have to be quick and agile, even in bulky pads. Not only is it a physical game for goalies, but it's mental, too. Goalies have to be able to bounce back quickly if (god forbid) a goal is scored on them. If an offender, middie or defender misses the ball, there's always a chance to reclaim possession. If a goalie misses a ball or misjudges her timing, then the other team scores. Offenders, mids, or defenders take heat for not winning the game, but the goalies take heat for loosing the game. Goalies have a hard job because if the defenders aren't doing what they're supposed to do, or are playing like crap, then the goalie has no hope, and will still be blamed for the loss.
Goalies are tough, courageous, determined, and extremely skilled players in one of the most aggressive sports out there. There's no one else like them.