hey!
I have curly brown hair thats 31" ( almost to my waist  :D). It seems like over the past few months or so, my hair has changed; the curls arent as full anymore-- they dont seem to have the same "boing" anymore! I already have thin hair, but it used to seem to have more volume. Is it because its longer now? I really am so confused!! :-/

Although I'm not a "curly girl", here are a few thoughts as to why your curls might be drooping.

If you have too much product build up on your hair, it could make it heavy and lifeless.  You might try using a clarifying shampoo and/or use a vinegar rinse to remove the build up.

The length and weight of your hair can pull the curls out a bit.  This would be more noticable at the scalp and not the ends.

Some people with curly hair do not wash their hair with shampoo - they use conditioner only, and this apparently helps keep the curls as well.

Good luck with you hair!