Sorcerer's apprentice noun phrase
A person who brought a process, event, or the current affair about but now is incapable of controlling it.
I feel like a sorcerer's apprentice now. I hold this party, but everyone ignores what I am saying.
John is in the position of sorcerer's apprentice now. He instigated this sporting event for children, but kids have been running around since they got into the field.
This phrase alludes to Goethe's song "Der Zauberlehrling," published in 1797 about an apprentice magician who, through hubris in his own skills, summons a broom to perform his chores for him, only to discover he has no means of controlling it.