Good Idea Bad Idea-The RL Edition

[I Started A Cult]

I'm sure the English-speakers in the audience remember an American cartoon entitled "The Animaniacs." Well, one of their running gags was a short sketch called "Good Idea Bad Idea." In it, a character demonstrated a good idea (Eg: playing the piccolo in a marching band) and then followed it up with a minor variation on the phrase that made the idea much worse (EG: playing the piano in a marching band)
Do any of you have personal philosophies that go along that line?

My cases:
Good Idea: Putting sea salt on caramels.
Bad Idea: Putting sea salt on literally any other desert item.

Good Idea: Buying candy at the dollar store.
Bad Idea: Buying headphones at the dollar store.

 

[Glitchipedia]

Good Idea: Rehearsing a play in drama class.
Bad Idea: Rehearsing a play in math class.

 

[Serperiority]

Good Idea: Giving candy out to children on Halloween

Bad Idea: Giving candy to children on any other day (pedo-*shot*)