i have loved leggings since i was in 3rd grade. there was this awesome girl named claire, and she was the kind of girl that was just sickeningly perfect but you liked her anyway- she had golden blonde hair, big blue eyes, perfect rosy skin, an athletic body, she was nice, she was smart, she was funny... yada yada yada. and she showed up every few days in the coolest leggings from talbots kids! red leggings, green, blue, black, brown...i wanted legging so badly. and so i got some. and ever since then, i have amassed a hugeeee collection of leggings and tights, both funky and plain.
of course, when they became trendy (along with indian slippers) two or three years ago, i was very put out, i wanted to be "original.' But I got over it and still wear my leggings with happiness because they make me happy.
the only requirement, so to speak, i think to wear them is nicely-shaped legs. wearing leggings, whether under a skirt/dress or by themselves, requires slim, shapely legs! sort of like fat girls wearing skinny jeans, or tummy baring tops - it is disgusting to see a girl (i know not her fault) with chunky, ugly legs wearing leggings. it is gross. but that is just my opinion.