Asked myself a MILLION times. It's not just Panerai too, it's all watches in general. Why do I really need more than one good watch, and one watch to wear to the gym?
My initial answer is that I'm missing something more substantial and meaningful in my life. Religion? Goals? When I am focused on another aspect of my life, I find myself spending less and less time thinking about watches. My online hits to places like this, and timezone etc. go way down. When I'm a tad depressed, bored, and inactive, it's the exact opposite. Who knows, I don't think that's the case with most watch lovers I know though. They all have pretty full, meaningful lives.
I think you could say it's part obsessive, if not collectible nature. If as a child you collected baseball cards, perhaps you're more prone to collect watches? What is really the difference between a 72 Tom Seaver and a 73 Tom Seaver?
My dad was a clock guy, he never understood how I could have so many wrist watches, when he literally had dozens of clocks all over the house..
I also think, it's a small way to reward yourself for working hard, grinding it out.. if your family is happy and taken care of, you're not broke, buying a watch, even if it's not all that different from one you already have (for example, I need another rotating bezel watch like I need thinning shears at the barber), it's a way to look down at your wrist and say it was all worth it.
In close, I don't think there is a be all, end all answer. For each individual it's different. I know for me, I've spent a great deal looking inward, or at the man in the mirror, and still don't have the answer. I go from loving having different nice watches, to hating myself for wanting them on a pretty regular basis. It's bi-polar for sure.
Thanks for the thought provoking question... Always enjoy forums like this for that exact reason..
WAG MORE Bark Less!