Taxing jitters

I’ve been up since daybreak, trying to control my rising anxiety as I approach tax-filing day (tomorrow, April 15th) here in the USA; later this morning I’ll visit a volunteer tax-preparer for senior citizens (I’m now 66) who will review my notes & initial attempt at filling out a 1040-A form. What confuses me is that since I hadn’t worked for pay & so earned anything in 2008, I owe no taxes, or so it appears (tho I did collect Social Security monthly.) I could be described as 'living on a fixed income' now, but because I have usually worked for pay & paid some taxes each year, it just doesn’t seem quite real to me. Most people would be be glad to pay no taxes, but all this bewilders me; I must not be alone. UPDATE: It was confirmed that I owe no taxes for 2008. A sympathetic AARP volunteer (I'm a member) reviewed my documents & e-filed my 2008 return, telling me to expect a $250 check as part of the economic stimulus pkg. After sitting a while in the pine-paneled library of the senior center, browsing thru Elisabeth Kostova's novel THE HISTORIAN (2005, set in Romania, about Vlad the Impaler), I rode my black bike back against a strong headwind & soon fell asleep at my keyboard. I woke to finish writing this.