Catching a giraffe drinking requires a lot of patience. They are very vulnerable in the drinking position, and will spend what seems like hours casing a watering hole before actually bending down to drink. Doesn't seem very evolutionarily advantageous to me, but I guess the fact that they can reach food when no other animals can makes up for it. At any rate, they do look pretty silly when they're drinking. Maybe they're so careful about where and when they do it because they're embarrassed and don't want to be seen looking goofy.