How many controllers do you own?
Three DualShock 4s (Magma Red, Black Ops III and Glacier White)
Five for Xbox One (Elite, 2x Lunar White, Forza 6, New version Black)
One for Wii U (Pro controller that I haven't used)
Two for PS3 (regular black DualShock 3s, one of which is from when they first came out)
Four for Xbox 360 (Tomb Raider, brand new black one, well worn Halo 3, well worn black one)
Several WiiMotes and WiiMote Pluses (got some with games)
My interest in buying new controllers didn't start until this gen. I didn't buy many last gen. A lot of the Wii stuff came from games like Wii Sports Plus and Zelda, IIRC. I don't like Wii much.
It's definitely an OCD thing. I have a fear of getting my controllers dirty, or them breaking/being defective, so I guess I obsess over that to the point where I always want to buy new ones so that I have perfect ones. And I've become obsessed with the different coloured versions, whereas I didn't care for decades.