Who are these Characters ?

Jo sent me this greeting today

I was like... who are these characters. I made the mistake of forwarding to the rest of the office asking exactly that. Then for the next 10 mins or so, I was bombarded with an onslaught of the most vicious cultural education of sorts. Some laughed at me, how could I not know these characters? I was thinking, why not? I really dont know who they are.

For those of you who are like me, these are comic characters who were really popular in the 60s or early 70s in Singapore- that's Way before I was born. Anyway they were still laughing at me during lunch & through the day. Is that so funny?