You are at your desk, everything is clear in your mind. The new game mode should feature a new energy system which permits to spend energies in change of doing a whole set of special actions in your RPG. You can throw bolts, run away from fights, hit with a sword. All with this energy system.
Then the engineer writes you on Slack: hey, can you check this? You see that nobody understood the vision, so that check your documents. “Look, is all there!”. They didn’t read the comments under the flow, your document was too long to read. The leader of the project says it’s too late. And the leader starts imposing own design, without thinking too much. Discussions starts, but in the end the vision changes.
You update your documents.
Documents that no one, except from you and maybe QA, will read. Satisfied you will shut down your PC. And hope for the best.