It is difficult to understand the universe if you only study one planet
When you attack the enemy, your spirit must go to the extent of pulling the stakes out of a wall and using them as spears and halberds.
Never stray from the Way.
The way is in training.
When you have attained the way of strategy there will be nothing that you cannot understand. You will see the way in everything.
If you are not progressing along the true way, a slight twist in the mind can become a major twist. This must be pondered well.