Ashamed? Never. It's no bother. Just listen to the advice
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So, it's illegal not to change your addresses with the Ontario Government within 7 days. They can fine you for this. That aside (since they already know you moved -- keep it for future reference): Service Ontario will give you a printed copy of the change (the green paper you talk about). Just bring that. You can state that you didn't know you had to change your address on the license, and once you noticed your insurance address was different, you went to correct it. No bother there.
The only suggestion I have is to not be afraid. To be open and honest. If you are in a legit relationship, and you can demonstrate that, then there is no worry about the interview. If you are nervous, they wonder what you are hiding.