Is it normal to meet people who keep quiet so as not to give majority advantages or let people know what they are thinking?

? what do you mean?

I know people who are quiet and private. but i think its just their character?

How do you know the people are successful?

Yes, quite normal to meet people like that in real life, especially in Singapore where things quite competitive. Some people don’t like to share their ideas or strategies because they scared others copy and do better, or they just want to keep their advantage. But not everyone like that one—got people who really willing to help and share also.