Performance problems?

Last week I was talking about the Spring framework with a team leader, and he was quite astonished when I told him we were not worried by performance problems using it. That sounds strange to me, as I was always told - and firmly believe - that you have a performance problem only when you experience it. Worrying about performance when you don't have problems could lead to overengineering, thus is not very good. Obviously you should try to load the system as soon as possibile, because you don't want to find out your architecture is completely wrong two days before you go into production, but that's a different story (and no, we did it and we don't have performance problems either).

As an aside, what kind of question is "tell me a method you'd use in Spring"? I normally care about my pojos, keeping third party's javadocs close at hand should I need them. I don't think I'm supposed to remember boilerplate syntax, and actually I don't - even because I'm not a one man band, but I work in a team where skilled people can do their job (guys you owe me one) leaving me free to do mine.