@ocdmn : "He also said to trust your training. how long he's been training again? and the result is showing now. so to git gud they need to train hard and be patient with it."
That's why it's a bad lesson. Sansui trained for hundreds of years. (I think, 200 ?)
Unless you're an immortal, you just not possible to follow the advice he gives to you.
At best a swordsman would be able to train for 30 years before his body begins to wither and makes the training irrelevant.
In the span of 30 years, sole training isn't the best. Real combat situations are important too. There are more risks and it's kind of a gamble, but it gives more experiences too.