I am sure this has happened to you. If you’re honest you’d admit to it. You’re busy, rushing from shop to shop, you need to get home before you have to go out again and do umpteen other jobs in a busy life which you lead. And then, just as you’d wish it the least, you see someone you know.
You do not want to stop and have a chat. You know this person will hold you up, talking about this and that, and sharing their problem at a time when you can least afford it. And you are too polite to say, “Why don’t you go away and pester someone else and leave me in peace!”
So what do you do? You pretend not to have seen them. You turn the other way. Pretend to be looking at some goods in the shop. Or better still, leave the shop in a hurry to avoid them all together!