What kind of part-time jobs are ideal for me?

I was last employed in 2008 for 3 months. My employment was terminated due to a lack of interest on my part. Last month I tried applying for a part-time job at a bagel shop and was declined because the owners were looking for a candidate who had worked 15-20 hrs per week for a period longer than 6 months. I am a full-time student and apart from the aforementioned employment, I have not been employed except for a few other part-time jobs which were not heavy commitments either. The manager said that on paper I did not make a favorable impression, although on the interview I came across as good. So what? Is it going to be like this for every part-time job I apply for, i.e., I did not make a favorable impression on paper? What are my chances?