The trouble with hair

It truly amazes me that every 3 to 6 weeks, I need to dye my hair because I have an inch of roots showing. And yet...my hair has not grown an inch. It amazes me that the hair I try to rid myself of grows so much faster than the hair I want to keep. I pluck my eyebrows every three days or so because they grow that fast. And yet the hair on my head does not. If I were to go a week without shaving my legs, I'd have a good 3/4 inch of hair...and yet the hair on my head does not grow nearly so fast. Somehow, I don't think this is fair.