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I took on the bookkeeping position at my former job, just prior to the firing of the bookkeeper. I knew nothing about the bookkeeping software and had to teach myself the A/R, A/P, payroll and tax payment functions in QuickBooks immediately to stay current. In my other position, I had to teach myself a graphics program to replace one that was becoming non-functional. How do I explain this "self-teaching" on my resume?