Because you are taking things that don't belong to you without asking.
Yes, you can even get caffeine poisoning, Good Luck
B:illegal drugs (I believe)
Answer:
CNS myelin is produced by special cells called oligodendrocytes. PNS myelin is produced by Schwann cells. The two types of myelin are chemically different, but they both perform the same function — to promote efficient transmission of a nerve impulse along the axon.