It has become increasingly common for people these days owing to the increased exposure to a larger world through QA based social media platforms to prematurely ask for advices on the viability of their ideasMostly seen with Quora, generic IRCs, superficial subreddits, which can be immensely encouraging or discouraging based on the people that chose to answer your questions as you are not always going to get an answer from an expert on the feasibility of your ideas. The other obvious thing I find is that of the implicit play of limiting-beliefsLimiting beliefs are those which constrain us in some way like lack of belief in one's own ability (imposter syndrome), the overestimation of the complexity of a project, will-power dissolution, etc when advicing others i.e., people who have limiting-beliefs about their own ability tend to extrapolate it to others when asked for advice(n=1).
I think it is a good heuritic to take the plunge and do it, at least most of the time. As Nassim Taleb says we are largely good at doing than thinking"We are largely good at doing than thinking, thanks to Antifragility"
—Nassim Taleb. This is not to say that you should dive head-first into a seemingly daunting project without any background knowledge or research, but that you shouldn't spend your time validating the potentialities based on the online responses which itself cannot be validated.
The best strategy at least in my opinion is to spend time becoming a definite optimist(Zero-to-One reference), and working on the idea (includes reading, researching, coding) to find out the effort required instead of seeking out premature effort-validation of seemingly infinite potentialities.
 Thiel, Peter. (2014). Zero to One
 Nicholas, Nassim Taleb. (2012). Antifragile: Things That Gain From Disorder