You must empty out the dirty water before you fill the pitcher with clean.
One cannot learn from someone whom one distrusts.
People used to play with toys. Now the toys play with them.
But one may say something and yet not be able to do it. Try, for instance, lifting yourself up by the bootstraps.
Better to be safe than to be sorry' is a remark of value only when these are the actual alternatives.
It is not important to have said a thing first, or best - or even most interestingly. What is important is to say it on the right occasion.