No, you can't deduct the cost of gas used for bar-hopping during 2007.

The annual exercise of filing income taxes can mean confusion and anxiety for millions of young adults who are doing it for the first time. For example, there can be uncertainty over whether a new worker is still a dependent on his or her parents' tax returns and which party, child or parents, can claim various education credits.

"There's a lot of stuff I didn't know you could deduct," said Matthew Snow, a 24-year-old who works in California as an information-technology consultant. "And I'm still getting used to the idea of paying taxes. It's a pretty good chunk of money."

The experience can be equally intimidating for recent immigrants.

Jose Mendez finds the U.S. tax system not only complex, but also more pervasive than in his homeland.

"In Venezuela, the income level to start paying taxes is high relative to America," said the 29-year-old analyst for On Semiconductor in Phoenix who earned an MBA degree from Arizona State University. "I'd never recommend that anyone who's not an accountant file their (U.S.) returns directly."

Surveys indicate many native-born Americans of all ages also are confused.

"They don't teach taxes in the schools," said Bob Schmidt, a retired engineer who now prepares free tax returns, primarily in behalf of moderate-income people, in a program run by AARP.

"A lot of people struggle with what's a credit or a deduction," Schmidt said, adding that many lower-income workers leave refund money on the table by not filing returns.

Chronically changing tax rules undoubtedly contribute to public confusion.

Researcher CCH Inc. now lists nearly 68,000 pages of analysis in its standard tax-code volumes. That's up from 26,000 pages less than a quarter-century ago.

One notable change in the code for this year is a new zero percent tax rate on capital gains and dividends. But it applies only on some types of investments, some types of gains (long-term) and some types of dividends (qualified). Plus, it's available only to certain people: those who pay taxes in the low 10 percent or 15 percent income brackets, which could include a lot of young adults.

Uncertainty over tax rules probably impedes some people from taking full advantage of money-saving options.

Mike and Miranda Kamman, who closed on a home purchase earlier this month in Phoenix, mistakenly assumed that mortgage-insurance costs weren't deductible, said Mike, a 24-year-old political consultant. That used to be the case, but mortgage insurance became deductible last year and will remain so for at least a few more years.

Many people can deduct investments in traditional Individual Retirement Accounts, and Roth IRAs offer the potential for tax-free withdrawals. Yet neither type of account is especially widespread, probably because of confusion over eligibility and other issues.

One survey by Fidelity Investments indicated that only 37 percent of existing IRA owners added money to their accounts in a recent year and that few people established new IRAs.

Uncle Sam even has trouble giving away money through the tax code.

One example is the earned-income tax credit, which offers a break worth up to $4,716 for lower-income taxpayers with two or more children and smaller amounts to certain other people.

Each year, the IRS strives to raise awareness of the credit, yet roughly one in four eligible taxpayers fails to claim it.

The IRS itself notes "eligibility requirements for the credit can be complex."

But even as tax rules become more numerous and complicated, software packages like TurboTax have emerged as effective and relatively easy ways to prepare and file returns, in part because they'll lead you through the process by asking questions.

Plus, free electronic filing is available for moderate-income taxpayers who start the process through www.irs.gov.

Snow and his wife, Mimi, already filed their income-tax returns this year with the help of TurboTax.

"I don't think I could have messed it up if I had wanted to," he quipped.