I’m a third year PhD researcher and was also working on a grant for my university for a similar topic as my PhD. I was asked to speak to some computing classes at a nearby college. I explained that I wanted them to ask questions whenever they arose and asked again for questions at the end. After class, as I’m packing up, one student approached me, told me I was wrong about many aspects of my presentation (a topic I’ve read hundreds of peer-reviewed papers and books on) and that I should “really do my research”. He then left without giving me time to respond.