When to start Social Security is a very personal decision that each person should make according to his/her individual situation. The temptation to retire 3 years early costs real money, 25% of full earned benefit, and should be made only after careful consideration.
One important consideration regarding when to retire is, will you receive enough money in retirement to pay the bills? The monthly impact of working 3 more years is a boost of 25%. In the long haul, that could be a sizeable amount of money. As a matter of fact, should you live beyond the age of 74, you will benefit by having waited.
There is another consideration to continuing working. Those additional work years will produce more income in all probability than your retirement income will amount to. In dollars and cents, waiting to retire until maximum benefits are reached is probably better.
Besides adding to your overall economic benefit, the stigma of retirement is avoided for a while. Some retirees do not prosper mentally in retirement. Those whose feelings of self-worth are invested in their jobs may regret retiring at any age. Once families are grown, everyone needs to keep busy doing something. Work, for better or worse, represents ones life accomplishment in many cases.
On the other side of the retirement question lies the benefits of early retirement. Personally, I took this option for several reasons. The biggest reason of them all was my ability to adjust my personal economics to early retirement. I am still able to work, but to enjoy less pressure on a month to month basis. I was ready to reduce my work load, and am happy that I did.
From the perspective of mental state-of-mind, I am still very active. No couch potato here! Early retirement has afforded me the time to do things that full time employment did not permit. I decided to forego income later on in favor of the freedom to do things now, while I still have the strength and energy to do them.
Each individual knows what is in their heart. We know what we want to do, and must prioritize for ourselves. I retired early for personal reasons that apply only to me. You must decide in an identically personal manner. Each of us has only one personal future, and the right to pursue it for ourselves.