When you are so obsessed with something it has planted a seed in your brain. This typically happens when something is so cool or new that you want to replicate the coolness/newness of the object/idea too much.
Can also be used in a mocking tone.
Person 1: Oh my god!!!! I just love the new Kanye West song!
Person 2: Cool.
Person 1: Seriously though I've had it on repeat for two weeks.
Person 2: Dude, you're obseeded.