A rather... prickly question!
To be honest, it's not possible for a human (or any living being) to literally become a pineapple. Pineapples are a type of tropical plant that grows on a stem and has a specific biological makeup that is quite different from ours.
However, if you're asking in a more figurative sense, I'd be happy to play along!
To "be a pineapple" might mean embracing some of the qualities that pineapples are known for, such as:
1. Being sweet and juicy on the inside (having a kind and generous personality).
2. Having a tough exterior (being resilient