A crashing bore British old-fashioned noun phrase
Someone or something that is very boring
I don't think I can make friends with him. He is a crashing bore.
I stopped watching that movie. It is a crashing bore.
She gave me the wrong book. The book was a crashing bore.
Mary doesn't want to talk with someone who are crashing bores.
People tend to remember the bad things others do and while they easily forget or get rid of others' good things.