It's always nice to hear that someone has come up with a different idea. It may not work out, but at least they were thinking. And sometimes the original idea begets another idea that sends you out in a totally new direction, and that one works.
* Spencer Silver was trying to develop a super-strong adhesive and invented the Post-It Note.
* William Spencer was trying to create a synthetic version of the malaria drug quinine, and came up with a beautiful chemical-based purple dye, instead.
* John Wesley Hyatt was trying to invent a synthetic elephant ivory (for a $10,000 prize) and ended up with the forerunner of plastic.
Keep fiddling -- you never know what you'll come up with.