As many have said...
Flashlights work on us on so many levels. It's power. Safety. Comfort. Certainty. How did you feel as a little kid when you were given a flashlight? You no longer had to fear the unknown of the shadows, you had a weapon that could eliminate it. If you were outside, your reach and your sight were no longer limited, you could send a beam of light to the tops of the trees, extending your influence as far as your batteries and tiny incan bulb allowed. The darkness, concealing everything frightening, could now be conquered. In many ways, I think we never really out grow that. We all tend to fear the unknown, and a flashlight combats the unknown and gives us power over it. It also makes us more powerful than those around us who don't have a light or don't have such a bright light, we're prepared for what the world will throw at us each night, we feel like a king and a hero. For some, it becomes something of a hero's quest to find that light that feels "right," like it's meant for you and your needs. It's a magic wand, spreading a sort of knowledge, extinguishing ignorance. And when you think about it, the light itself, the actual photons being emitted, is rather magical; isn't it amazing to think that we're holding a device that is emitting a beam of energy particles in such a vast quantity that they're able to bathe an entire room in its energy? It's a light gun, if you're into guns. It's the fire at the mouth of the cave, it's Luke's lightsaber, it's Roy's six shooter, and it's Merlin's wand. It's a toy that kept us company as a child that we can reach back and pull into our adult lives as useful tools. These are powerful objects that can evoke strong feelings and attachments within us.
On a material level, a high end light has a wonderful essence of quality, craftsmanship, toughness, gizmoness, and functionality to it. It's a connoisseur's hobby, one in which we can revel in the refinement of our taste and the sharpness of our eye for detail; we have a special knowledge and appreciation and it makes us feel like we're special for it. Some fetishize watches or guns (as in nerdengineer's comparison) or jewelry or other gadgets, it's the same basic thing. It's quality, it has value, it's shiny (as Zenster pointed out), it's uncommon and special, you can see that someone had to put a lot of thought and care into creating it, it makes life better in a way that's significant to you; it's a rather magical object even before you get to the utility of being able to see in the dark.
Some people just naturally want to collect things. When you think about it, flashlights are a pretty natural thing to be drawn to collecting.
As for CPF, it's largely the people and the camaraderie. It's nice to go into a crazy hobby knowing there are thousands of other crazies that totally understand where you're coming from. There are some really good people here, and we tend to have a lot of fun, as opposed to most other forums that constantly degrade to children slinging naughty words. The people here tend to be a lot more down to earth and less insecure and nasty. It's a good place to meet some nice like-minded friends, even though you probably won't get to actually meet many of them.