They were either joking around or they have such low standards that they can't fathom why someone would further their education like that. I once worked at a place where people held it against me that I had a college degree, talked trash about another girl because she was applying for her master's to better herself, and bragged about how they didn't want their kids go to to college because such a degree was useless compared to just getting a job. They just had a very narrow mindset - I think in their opinion education was a waste of time and money, and they probably imagined those people later homeless and without jobs or something - they didn't realize that people actually go onto better jobs and teaching positions, research, etc after they have furthered their education probably because they weren't familiar with those circles. Most hadn't even been to college, or if they had attended some college, they just had no idea what work their was beyond what they saw around them in their regular world - mechanic, beautician, etc. I think if someone said they wanted to go to medical school, they would have understood that, or lawyer - they understood that kind of thing, but the world of academia was a total black box to them. If they were making fun of you, realize it was their own ignorance and/or insecurity/jealousy and be glad you know your goals, I think it's great that you want to go far