I am.

A companion and friend.

There when you need a hand.

Reclusive and sometimes exclusive.

These things are who I am.

A warm smile but a mystery all the same.

Like a wild beast that can't be tamed.

Critically thinking and mentally critiquing 

What I do is who I am.

An expert in nothing but experienced in many. 

With a quick wit to shut down

and a sharp tongue to keep you on the ground.

What I say is who I am.

The sweetest thing during my season

but pairable when underripe or rotten.

A mystery to all but never will I fall

This is who I am.