"It is common sense, isn`t it?"

Care to elaborate, vociferous one?

Define "common sense" for us then explain how the phrase "look before you leap" and "he who hesitates is lost" both qualify as good advice when each is considered common sense.

Opposites Attract - Birds of a Feather Flock Together. (common sense)

"When deciding whether to walk on the ice of a frozen lake, use Common Sense
During a first aid emergency, use Common Sense.
When traveling in a foreign country, to be sure you don't offend people, use Common Sense.
If you are alone when you go into labor, keep your head and use Common Sense."

Tell us how you can use common sense in the circumstances above to solve the problem.

Might I suggest that we dispense with common sense and stick with facts?