I speak with no mouth, hear with no ears and come alive with the wind what am I?

I feel like flying lightning, but I do not feel like an electric shock. You might experience me in a quiet meadow in a summer night.

I resemble a white puff, but I do not float in the sky among the birds and planes. You can make clothes with me.

In a flock of brethren, I arrive. In shallow waters, I take a dive. I come out with a fish to eat, then on the beach I rest my feet.

I am soft and sweet, a summer delight, yet deep inside, my heart is tight. But in a castle, I'm known by name, kidnapped often, it's quite a shame!