Question

Why do we feel annoyed?

Answer 1

it's an emotion of humans just like smile .

Answer 2

Meaning of annoyed- is to get angry.
We get annoyed not because of anybody else, but because we are irritated inside because of something that it didn't go the way we expected or wanted. When that happens we tend to show our sadness to others in the form of anger or annoyingness which leads to more and more irritation in us. But remember, this irritation only results in harming ourselves than harming anyone else.  And do we find joy in harming ourselves? No, definitely not. So the only way to get rid of anger is to LOVE everyone around us. This will make our mind calmer which results in happiness. So let us love everyone around us.
HOPE IT HELPS YOU.