You have to negotiate all time in your life. You have to negotiate always. It's the life by itself.
At work, in your house, with your friends, your couple, your family, at school. Everywhere is place to negotiate.
In your childhood, when you are teenager, in your mid-age and when you are elderly. Every time is to negotiate.
Since you were born till your death. Always, always, always...
You can see the profit, if you know how to do. But, if you don't know, surely you will lost more than you can win. Wait the moment and then take advantage of it opportunity...