If someone has stolen your idea or taken undue credit for your work, don't let it upset you. Learn from that experience and move on as swiftly as you can. Life is too short to dwell in the past, and fall in the trap of self-pity and misery. In my experience, those who steal the credit and ideas of others shamelessly, often don't realize that they are actually increasing their bad "Karma" by their wrongdoings, and that bad Karma quickly catches up with them in no time. Be assured! Time takes care in sweet and mysterious ways - always! Never forget that nobody will ever be able to steal or take away your creativity, ingenuity, and inventive mind, even though they may have stolen your one idea at one time only. Your divine spark of intelligence will continue to illuminate the world, even after losing that one idea - because surely there's plenty more where that came from!
Deodatta V. Shenai-Khatkhate