Some people will choose to start collect CPP at 65 years old, but continue to work and earn an Income. In this case you want to be aware that if your Income is over a certain amount (I think about $47,000), then the government will claw back some of your Old Age Security.
A consultation with a Tax Expert is always advised when it is time to consider where to invest, and how to retire. The savings of avoiding a bad decision is always worth the time.
Again, I hope this helps and clarifies some of the issues.
I helped a single mother set up a budget who was in a Negative Cash Flow situation. She was so disciplined, that she amazed even me with her results. Within 3 years she was not only out of debt, but she was contributing into Retirement Savings.
I was impressed. She was thankful.