One of the greatest things is to see a hippo yawn. Their mouth opens almost 180 degrees displaying a massive throat, tongue and teeth. When god created the hippo, he asked if the hippo wanted to live in the water or on the land. The hippo said the water. God said fine, however, you can not eat the fish. So, the reason the hippo opens his mouth so wide is to show God that he is not eating his fish.
Si-mbaya means not bad in Swahili. It is a common response. when someone says "Jambo," hello, people reply by saying si-mbaya. Not bad. Even if things are bad, they say with a smile, si-mbaya. Its all a matter of context. I have my family, I have food, I have shelter. Not bad.