Glen of Imaal Terriers are born with a built-in "pack" need. They will spend the rest of their lives making sure they are in one. You must expect to spend the next 12 years establishing and maintaining your position as that leader.
You will have to remain a benevolent dictator to your dog for those years, or it will take over the position, and with it, your life and your home. You and your dog will live either by your rules, or his, and you do not want to live by his!!