People don't get that, on a large industrial scale, you actually have to think about supply. They think you just spend money and supply shows up because they are used to thinking on a household scale where supply is generally infinite for anything they could possibly consume.
I think one pervasive economic fallacy is that any amount of money can fix anything. We just need to find someone to write a big enough check, either the government or wall street and all those batteries will materialize instantly out of some technology horn of plenty. This has driven the focus on "stimulus" and "aggregate demand" in various forms of economic dialogue. We could use more supply side thinking about very large problems that the economy faces, especially in the public sector. Health Care, for example, is one of those things where, if you're not thinking about supply, spending more money just makes everything more expensive.