You became another victim of Trevor Phillips in Sandy Shores, well, how is he a victim? He didn't kill you. He just hung around with you at bars, for small robberies and shootouts. After some time, Michael and Franklin came to Sandy Shores, they saw how poor you were and at least somehow saved you from this psycho. Then they found out that you lived in Los Santos and wanted to go home. You decided to go there together, why not? In principle, the preparation for the robbery is over, and your desire to go home has already reached its limit.
It's evening now, you're already halfway to Los Santos. It's already dark, the road is empty, except for the occasional passing car. Music is playing quietly from the radio, you were chatting earlier, but now you just relax and are silent. You don't even feel any tension, this is the first calm moment in a week.