Safety Net
He: Hey you, I picked up a new hobby.
She: Really, another one? What is it this time?
He: Tightrope walking. It is so exciting.
She: I bet it is. Are you not afraid to slip and fall down?
He: A bit, but I am prepared: I mounted three ropes next to each other, so if I slip off the middle one there will be still one to each side that I can step onto to hold my balance.
She: Sorry, what was your final grade in physics again?