Of course, everyone's situation is going to be different but count me among those who, for a variety of reasons, couldn't practically speaking retire at 65 even though I was eligible for "full" SS benefits at that age. I ended up retiring at 67 anyway and SS eligibility had nothing to do with it. Do I have regrets or feel as though I somehow lost a couple of years of fun? Nope, not really. The circumstances were what they were. Additionally, like a lot of working folk, to some extent I felt like my work defined a part of who I was. Even though I knew that I could easily pull the plug at 67, I had a difficult time actually making that decision and committing to it. It took some substantial pushing from my wife to get me to commit.
Of course, shortly after I retired we took our first extended trip and I was completely sold. For the first time in my life I got to travel without carrying a work laptop, or worrying about those calls that I always got to remotely assist with the latest "emergency". So, while I don't regret those 2 years of working, it took almost no time to fully embrace my new freedom.
Scott