A question that I answered in a previous column brought a small avalanche of mail, mostly from readers who were aghast that I would suggest they save such a significant portion of their paychecks for retirement. It was money they insisted they could not afford to save. I can only imagine that for a person who saves nothing, suggesting they should be saving thousands every year can be shocking or perceived as impossible. Here is one of those messages: Dear Mary: I am a 34-year-old college grad. My school debt is approximately $46,000. My car loan is $8,500. I have a chronic medical condition that costs me thousands each year. I was reading an article that you wrote where you told a reader that she needed to save the maximum allowed in her 401(k), which I believe was something like $17,500 a year, plus save an additional 10 percent of …