Ehh, phones have mics, and most people have a phone in their pocket these days. If you’re walking around in public, you should know that there is likely a mic nearby, so you should act accordingly. I’m not condoning public recording, it’s just the world we live in. Look up your local laws, some places require both parties’ consent for recording (honestly unrealistic these days but can be helpful in court), and some places only require one party’s consent (meaning people are allowed to record their conversations with you without telling you).

Remember not to incriminate yourself. It’s good to know when to be quiet.