I know on which side my bread is buttered.
Cut your coat according to your cloth.
Be the day never so long, Evermore at last they ring to evensong.
Who will in time present pleasure refrain, shall in time to come the more pleasure obtain.
There are none so blind as those who will not see. The most deluded people are those who choose to ignore what they already know.
It's no use closing the barn door after the horse is gone.