I've learned so much from this summer job.
I've learned that house owners in our neighborhood tend to own dogs.
I've learned that many times dogs are much smarter than their owners... (the owners would many times leave the dogs running loose, despite having asked us to deliver)
I've learned to run fast. Very fast. Or at least faster than the dogs. Or at least faster than the chained dogs :-)
And I've learned that knowing your users is great, and lets you have a better product or service.
But I had 60 users. That's it.