Yes unfortunately you quite often come across people who are critical of your research or doubt it will work (sometimes because they don’t want the competition!). My response varies. Sometimes I’m able to be like well actually, here are my results proving you wrong, SO THERE! (Although obviously in a more polite way!). Other times I can see why they doubt it would work but I am able to explain my reasoning behind why I think it will. And then there’s the good old fashioned ignoring technique.
Yes I’ve definitely had people doubt my work, it can happen a lot when you give scientific presentations at conferences, because there are many other scientists in the room who are working on similar things, and each one thinks they know more than the others!
I’ve been asked a few nasty questions when presenting my work – in those situations I take a deep breath (!), then explain the reasons why I think I’m right, and then they just have to deal with it! 😀