Serious as a Heart Attack simile
To emphasize that you're extremely serious about what you're saying and not joking around.
A: "No, it can't be! You must be joking!" B: "I'm as serious as a heart attack!"
A: "Are you sure you want to go there all by yourself?" B: "Of course! I'm as serious as a heart attack!"
To think or consider something seriously
To have done something really stupid, grave, and irreparable.
Said when one is absolutely serious or not joking in any way
If you say that someone or something is too hot to handle, you mean that they are too difficult or dangerous to cope with.
When a matter becomes serious, or problematic.
This expression was derived from the serious medical condition when someone has a heart attack. Because this is a horrible, dangerous, and life-threatening event, it is not funny at all. It represents something serious. This expression became popular in the 1960s. People often say this to show that they aren’t joking whatsoever.
people often do irrational or foolish things when they are in love.
I and my boyfriend have decided to get married in the summer. I don't think that's wise, since we won't have enough money saved by then to set up house. But then, one cannot love and be wise.