A man asked a novice software engineer to build him a shed. He came back the next day and saw that the engineer had poured the concrete foundation, and it looked pretty good. He came back each day, and each day the shed was looking better and better, and when it was done at the end of the week the man was quite pleased.
The next week, the man asked the engineer to build a treehouse for his kids. He came back the next day, and saw that a mass of scaffolding had been erected, some idle workers were standing around, and large plywood frames were being hoisted up into the canopy.
"What's going on here?" the man asked the engineer, in bewilderment.
"We're getting ready to pour the foundation," the engineer replied.