What's something that i've done in my life that is related to physics

That's a very difficult question to answer, because you give us
no information regarding what you have done in your life. 

We can only assume that you have most likely breathed on occasion,
floated on your back in the ocean, lake or pool, maybe fallen off of a
ladder or out of bed, felt the warmth of the sun on your cheek, seen
a rainbow after a rainshower, heard the sound of thunder during a
summer storm, taken a trip in an airplane, and waited for a cup of
hot chocolate to cool off.  The richness of any of these experiences
is greatly enhanced when you understand some of the Physics involved.

The main components of the central nervous system are
B)The brain and spinal chord