My response to that was "I appreciate your concern about my life, however, I am enrolled in college and have I've been taking 18 hours each semester for the last four years. Also, I have made Dean's List each semester I've been in college. I graduate in May and I'm  waiting to hear back from graduate schools I have been applying to. I'm working two  jobs to pay for tuition so I'm not overloaded with student debt. I work "here" because it's one of the few jobs that will hire a college student with an hour commute each way to school. Now, again, please enlighten me on how I'm wasting my life." 

Was I wrong to reply this way to a customer? I didn't say it rudely. I'm just tired of customers saying telling me I can do so much better if I had gone to college. It's like, because I chose to live at home (and now with my boyfriend still in the same town) to save on having to pay room and board, they automatically assume I'm not going to school. I don't think I was completely wrong, but part of me thinks I shouldn't have said anything. What do you think?