I am the good shepherd. I know my own and my own know me, just as the Father knows me and I know the Father; and I lay down my life for the sheep.
Jesus know His "sheep" (and one of them is me) like no other shepherd knows sheep. Jesus employed the terminology of shepherding to answer His enemies who wanted a very different Messiah than He was. He explained that unlike other parties who might be interested in sheep (thieves, hired hands, wolves), He alone was the good shepherd.
The audience to whom Jesus spoke knew all about shepherding, probably much better than must of us do today. And they knew sheep required constant care... that shepherds got to know their flocks well as they tended to them. The sheep were comfortable only with their own shepherd and would not follow strangers.
Jesus builds on this to explain that the way He knows His sheep, the relationship He builds with us, is stronger. He brings an intimate friendship to His flock. It is a relationship just like the one that He enjoys with the Father. That's what makes Him the "Great Shepherd".
Several times in John 10 Jesus emphasizes that as the "Great Shepherd", He will lay down His life for His Sheep. What's more, He will die and rise again for us. Unlike any earthly shepherd who might risk life but would not die for a flock (after all, if the shepherd dies, the sheep will scatter and the predator will win) Jesus would die, rise again, and bring His flock together, obeying His Father by so doing.
As one of Jesus' flock, I am known and I know Him. I am led by my Great Shepherd. I know Jesus, and in seeking to know Him, I know the Father. I am comforted by His Shepherd's staff, the cross that He bore for me. Because He willingly laid down His life and took it up again I can have life and have it to the fullest! That is why I will follow Jesus.