Many times I have answered questions only to be told to cite it. So I research and find somebody has already published it. With as much brains around here is it not possible to arrive at the same answer and not have to cite everything. I believe Einstein was a victim of this. When I draw a correct answer or even an answer that is a theory without proof do I have to cite it if I came up with the answer myself?

• "Many times I have answered questions only to be told to cite it." I believe this refers not to providing citations for your claims, but to providing citations for direct quotes and images you use. Can you give links to specific instances? "I believe Einstein was a victim of this." A victim of what? Are you seriously comparing yourself to Einstein? – ACuriousMind May 6 '16 at 9:37
• @ACuriousMind He was being called a plagiarist when he just arrived at the same formulas and solutions as other physicist . – Muze May 6 '16 at 21:05
• I have yet to see evidence for you being called a plagiarist merely for arriving at the same formulas and solutions as other people. – ACuriousMind May 7 '16 at 10:39
• @Jen, re this comment, now that is an assertion you need to back with evidence. – Emilio Pisanty May 8 '16 at 12:59

Now, we aren't as hardcore as a journal or conference. But for the most part, we expect answers to be supported by facts. These facts can include derivations and proofs if you did the work yourself and it is (mostly) original. And if the statement is so obvious that everybody in the field knows it to be true, then no citation is needed. For instance, nobody except a troll would demand a citation for $e=mc^2$. But if you came out and said "The equation you want is $e = mc^2 + 10$" -- well, you better be prepared to either cite where that comes from or provide all the details of how you derived it because that is not considered totally obvious to the experts.