PM Lee Hsien Loong and Ho Ching ride the train and commuters didn't care

The following is a letter from a reader
—
Letter by Chan Chee On
I was surprised to see PM Lee and his wife Ho Ching take the train today. I was more surprised to see that many people did not recognise them, or greet them. The security person though looked very nervous.
It is encouraging to see our Prime Minister take the train like that to see how ordinary people live.