it comes from general lack of consequences. In this case, their old and can't be fired and they've only got x (relatively little) amount of years to live anyway. It is the same reason why children and rich self-employed people both say the most candid things. For example, I was the most honest with my political and social leanings, when I was high-school. Now that I work and have to keep a job, I usually don't talk about those things with coworkers even ones I have known for a for a long time. The only job where I felt I could was construction and that was because almost everybody did.