A transformation from 'wa lan eh' to 'wa lau eh' then to 'wa Rau ea'. Originally 'lan' is a bad word mean 'dick' and make the phrase means 'holly shit' or even worst 'fuck man'; but then some educated people like Singaporean try to be more polite so they change 'lan' to 'lau' which means 'old' and make the phrase meaningless just for sake of espressing it politely. One day, I came up with 'wa rau ea' actually not much difference with the 'wa lau eh' just for fun. A friend of my found it cool and he started to change many words with initial L to R. For those who speaks 'hokkian'; try to change any word starts with L to R and you will find it funny.... Rin nah be....