Answer:
Even the oldest ones can be described as current, but a little mainstream.
A locked sphere without hinges or key. Break me open and golden treasures you'll see
What never ends but you always have it
Its fleece is warm and wooly white. And when you lie awake at night, count it and you'll fall asleep. What is it?
What is born long, dies short, and spends its life leaving a trail?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?