You can't go back, just go forward. If and when you decide to change careers, go forward and don't go back. Make sure before you ever make a move that it truly is a better opportunity overall. There are no guarantees that the grass there will be any greener. Once you arrive at the company where you think you can stay for life, do what it takes to conus lily win there. After all, it's the right thing to do and it models the way for others.