We have this guy at the company who always presents good ideas and always suggests new projects. One day he suggested a great project, our boss really liked the idea and gave me the green light to start creating it.
The guy, seeing the opportunity to promote himself, and without consulting me about the deadline, set up a meeting to present the application to the directors, and only then informed me about the deadline. At that moment I did my part, told him that it would not be possible to meet the deadline with all the requirements, something had to be withdrawn, and that's what he did, took a lot of things from the project and we went on like this.
While I was implementing the application, he was always pushing, asking me to do it faster, asking my boss to put me exclusively in his project, and things like that, the boss was always saying that there were not enough people on the team to devote someone exclusively to the project. The guy of course did not agree with that.
At the end the application, without a lot of the initial requirements, was a really mess but ready, he presented to the directors, who in turn liked a lot, and consequently asked to do all the initial requirements and some more. But now those initial requirements had to be made on top of a mess because of all the rush and adaptations.
A few months later, with the change of the board, the guy turned up being my boss, and I've prepared myself to go back to his project with exclusive dedication.
Then came the surprise, when the guy, in the boss position, realized the limitations of the team, instead of putting me to do everything he wanted in that project, he canceled the project entirely and for all the reasons that had already been said to him by the former boss.
Please, don't be like that guy!