Back in 2011-2013, I fought really hard at work to get funding for a new product, based on a principle that I came up with by myself. I explained it to my boss the simplest way possible, and when he rejected it, I explained it to his boss and then to that guy's boss. The higher up the ladder, the more confident these guys were that the concept wouldn't work. Enter 2017, and now the exact same concept is being developed by a consultant hired by one of the very same higher-ups who told me that the concept would never work. I've clashed with that particular guy a dozen times before, and this just seems like the final straw, now that he's trying to leech credit for my idea and doesn't even have the decency to involve me in any way in the grunt work to get it done, hiring a really expensive outside consulting firm to do something for which I laid the groundwork while I was studying at the university.