... it can often be profitable to try a technique on a problem even if you know in advance that it cannot possibly solve the problem completely.
Terence TaoUltimately you should follow advice not because someone tells you to, but because it was something that you already knew you should be doing.
Terence TaoPointing out that countless great mathematicians had tried to solve the problem and failed before you came along is in particularly bad taste and should be avoided completely.
Terence TaoUnsolicited surprise requests from strangers are essentially guaranteed to be met with a negative response.
Terence Tao