Do you, user, dare?

Sometimes I'm asked if we tested enough. As tester I'm tending to say "You can always test more". What is enough? There are dozens of answers when to stop testing. It mostly depends how many time, budget, risk etc there is.

Recently I was asked by a key user who was responsible for testing his part of the application. The key user had to give advice to his manager.

I could reply his question with testing terms like coverage, open issues, risk there is and what more. Only I knew that the answer would be: "I'm not sure, I think so."

I used this example:
Imagine you have to buy clothes for your self. You walk into a store and pick a trouser, underwear, T-Shirt. You like the color of the clothing only the T-shirt could be without that funny picture. Do you, user, dare to go out on the street with those clothes? Do you, user, dare to do it know based on the winter season and no coat? Do you, user, dare to approach your manager in those cloths as you know your manager likes formally dressed employers?

Do you have the same feeling about the application and do you dare to give advice? Can you answer me the question did you test enough?