- If you received any 1099s for contracting work, or W-2s for hourly work, the IRS also got copies of them, so they know what you made. - If you did receive any W-2s, chances are your employer also withheld income so by not filing, you're losing some money you would have gotten if you filed.
It's too bad you don't have any income, because if you did, you could write off all kinds of startup expenses as a business expense. Computers, a dedicated office in your house, a percentage of utilities and rent (sq. foot of office/total sq. foot of house), marketing expenses, books, tools, etc.
I highly recommend that you take advantage of all of these deductions when your startup starts to make money. Even TurboTax can walk you through them all; you don't need an accountant.