Maturity, exposure, knowledge, learning, inner strength is more important than hypocritical manners, formalities, packing, decorations.
If you own strength, knowledge, expertise , you get much time to learn manners.
A five or fifteen days rehearsal is enough to prepare yourself for a working dance performance.
But a whole life may not be sufficient to acquire knowledge, strength.
You can master table manners in a few days (hours) training.
A whole life is required to be District judge, High Court Judge, Supreme Court or Nariman, Salve, Madhav Menon.
Learning and sharpness counts. Manners alone would not. Even manners would not come without sitting beside and perhaps parallel with an able pre trained seniors.