We might have very good Chi Sau skill and even be very good at fighting, but if we are not aware of what is happening around us, in the end we will still lose.
A good Kung Fu man or martial artist needs to know everything that is happening around them, whether they are standing, walking or even resting. There was once a great master resting at home when somebody walked into his house. Straight away the master woke up and came down to meet the person. Even when the master was sleeping he knew everything there was happening around him. Of course, whether he wanted to wake up and deal with the person or not was up to him.
When we are in a strange place we need to be aware of what is happening around us. If a stranger approaches us, we do not know them and so cannot tell whether they are friendly or dangerous, but we must be able to respond to them. Even when we are walking, our eyes and ears must be aware of everything around so we will not be caught out unaware.
It is the same in fighting. Before we fight we need to know the area around us. Then we will not be pushed up against a wall, step on something harmful or trip over something. During training everything is set up for us and when doing Chi Sau we know the space and partner, but in reality the enemy will not hold back from harming us and so it is important we know what is around us. We may wonder why are there so many accidents and people getting tricked and robbed but It is because they lose their sense of awareness. An animal will be alert for anything that might harm them. Even a domesticated cat, will sleep but keep their senses aware if they are not sure that everything is safe and you can see their ears moving as they listen to any sound that is different.
So we should be like this and be aware of our surroundings and the people around us. Someday it might save our life.