It is rude to refuse a polite request.
Jamal wanted to go to Costco, but the greeter at the door asked him to put on a mask before he could go in.
Jamal wants to decide whether to put on a mask.
Jamal decides to put on a mask since he doesn't want to cause any trouble.
Jamal doesn't want other people telling him what to do, so he decides to leave.
The greeter is glad that it didn't take him that much effort to make him put a mask on.
The greeter doesn't understand why Jamal acted that way since he asked nicely.