Meaning: Do not expect anything much from anybody people changes.
I beg to disagree with this interpretation. The proverb and the meaning purely differ.
"As bitter kola sound for ear no be so e dey sweet for mouth" This is saying that as sweet as bitter kola sounds to the ear when chewed, is not that sweet when you taste it.
This means that there is always unknown truth or some kind of pains in everything that seems good or perfect.
I want to use cryptocurrency we are into as an example.
Many people will hear that there is money in the crypto and jump in, not knowing that a time like this when the market will be red exists.
So, everything is not always as good as it is presented, it is when you enter into it, you will discover the untold part.
The meaning has nothing to do with people changing.