[TowerTalk] dipole question

[Merlin-7 KI4ILB]

 I am new to ham so forgive me if this is a dumb question.

 I have an inverted v  parallel dipole, my question is about grounding. It is fed with 50 ohm coax to the top of my tower.
 I have a spark gap lightning arrestor connected to the coax outside my home where it goes thru the wall connected to 3 ground rods.

 So knowing that, how does the side of my dipole that is connected to the shield do anything if the outside of the sparkgap is grounded?

 thanks and 73s