Science is unique compared to other disciplines in that what we do (experiments) usually fail more than they succeed. Furthermore, our hypotheses are often naive and/or just plain wrong. As such, we all have to get used to failure, because it will happen often in our careers. This does not make you an imposter, especially if you can intellectually defend your work. These failures have to be viewed as learning experiences. As so elegantly put by Martin Schwartz here,
Science makes me feel stupid too. It’s just that I’ve gotten used to it. So used to it, in fact, that I actively seek out new opportunities to feel stupid. I wouldn’t know what to do without that feeling. I even think it’s supposed to be this way(1).
Your grant will get triaged, and your paper will get rejected. The key is having the fortitude to mentally overcome these failures.
1. Schwartz M.A., The importance of stupidity in scientific research. doi: 10.1242/jcs.033340 June 1, 2008 J Cell Sci 121,1771.
UPDATE: @SciencyCheese pointed out another quotable quote from the geneticist J.B.S. Haldane. He stated that acceptance of an idea (in his particular case, life expectancy tables as predictors of future life expectancy(2)) follows four stages:
1. This is worthless nonsense,
2. This is an interesting, but perverse, point of view,
3. This is true, but quite unimportant,
4. I always said so.
2. Haldane, J.B.S., Journal of Genetics Vol. 58, page 464 (1963)