Wow! That was interesting. You always have such good stories!!
As for moi, it was my urologist that pushed the water, as I was very prone to UTIs. And, I was developing allergies to some major antibiotics--due to multiple prescriptions for these--down through the years. So as an important preventative measure, I follow his suggested routine daily. It has been extremely helpful to me.
Now as for lubricating (shoulders, hips, knees, etc.) joints, many medical people agree on that one, too. From what I was told recently, it is more important for older people to up their water (or liquid, fruit, milk, juice, soy milk -- whatever, etc.) intake specifically for this reason.
It may be that individual results vary on all the above, so I can only attest what has worked for me.