I hate it when strangers try to talk to me in public (e.g., on public transportation, at work). I absolutely do not care what you have to say, what you do, how your day went, how many pets you have, what your hobbies are, or where you spent your holidays, and at the same time, in no way do I want to share any details about my life, not out of privacy or anxiety of speaking but out of sheer annoyance and indifference. However, most of the time I do not want to insult the person that tries to talk to me in any way, so I just stay silent and try to endure this torturous assault until I find a suitable moment to get away.

People should try to sense when someone wants to get left alone and leave them alone. I don't know how much you communicate that and misunderstandings do happen. Anyway regardless of whether someone just doesn't get that you don't feel like talking or whether they do not care, when just giving short direct answers to questions that only maintain the minimum level of friendliness does not work to get someone to stop talking to you you are doing both of you a favor by directly, but politely telling them that you do not feel like talking right now.