Vantage points and the real question

I'd like to share with you a simple exercise I take students through. Or anyone who cares to listen, frankly.

Here goes the exercise:
Every morning I walk into the bathroom to brush my teeth. One particular morning I pick up the toothpaste and find that someone has left the cap off. Something that happens all the time and annoys me a lot. I shout out: "Who left the cap off the toothpaste AGAIN?"

No one replies.

So hold the above picture in your head. Better still, freeze frame the film. You are a design student with a brief to identify NPD opportunities for toothpaste. You have just watched the above event on film. Listening to me, you would quite rightly think you have identified a need for caps that are connected to the toothpaste tube or caps that somehow encourage people to close the toothpaste tube. You may well come up with many concepts around toothpaste tubes and caps which cannot be separated for very long. Whatever, my cry has sent you, the designer, down a specific design path.

So let's replay the above scene again and think to ourselves: what is the real question I (me the subject) should have asked? Instead of trying to identify the culprit (one of my three kids or my wife) perhaps I should have taken a step back and asked:

"How do we make sure the cap is never left off the toothpaste tube again?"

This time, family members not feeling threatened, give me a bunch of suggestions.

I could also have asked:

"How can we make sure the toothpaste is put away in the drawer or cupboard - forcing people to replace the cap?"
"How can we not have toothpaste at all to avoid the problem of the left open cap?" Extreme I know.
"How can we never have to take the lid off the toothpaste tube yet still be able to use to it?"

Once asked, the designer has many more routes to travel down, and more opportunities begin to reveal themselves.

Another way of describing this process is what I can only explain as finding new vantage points to look at the same situation. Vantage points the participant will never see or speak from.

Thoughts?