Not to talk about someone, someone bad may happen to the person.

Taboo told by my mother: Not to talk about someone, someone bad may happen to the person.

Now I really take this seriously.

In one morning, we were talking about our colleagues' wedding. Chatting away how special is their wedding, while looking at their photos. The moment we stop talking about them and back to our work, someone came to our office and told us the bad news. An accident happened in Mexico Gulf, and he is in the missing liferaft. It was a shock to us. One moment we were talking about him, one moment he might be forever gone.

A friend said perhaps the moment we were talking about him, he was not around anymore. It is a remembrance of him, when we were talking about him
.
RIP.

Then I really get it. Nowadays I don't really talk about someone who is alive, not going to talk about his favourite food, his hobby. Keeping to myself is enough.

There were many times when I mentioned someone, that person would appear or contacted me.

There is a chinese saying:

Don't talk about someone during day time, don't talk about ghost during night time.