Well, we are finally starting to pin you down. Please explain where in the statute the mere act of following someone invalidates its application:
A person who is not engaged in an unlawful activity and who is attacked in any other place where he or she has a right to be has no duty to retreat and has the right to stand his or her ground and meet force with force, including deadly force if he or she reasonably believes it is necessary to do so to prevent death or great bodily harm to himself or herself or another or to prevent the commission of a forcible felony.
The qualifications of the statute are fourfold.
First, the person using force must not be engaged in an unlawful activity. According to Zimmerman's account, he followed Martin, and asked him a question. No problems there.
Second, the person using force must be in place he is lawfully permitted to be. Zimmerman was in his own gated community, using the public streets and walkways. So far, so good.
Third, the person using force must be facing an attack. Zimmerman claims that after asking Martin a question, Martin responded with an insult and then punched him in the face. Attack threshold met.
Finally, the person using force must reasonably believe he is facing the threat of great bodily harm. Eyewitness has Martin on top of Zimmerman pummeling him. Zimmerman had a bloody nose, swollen lip, and cuts on the back of his head when police examined him. Great bodily harm is on the table.
Now, all of this is of course dependent upon what Zimmerman reported being the truth. On the surface, his story seemed credible. Further investigation by the police revealed a fact pattern consistent with what Zimmerman had told them.