Yes knowing what side of the road to drive on and understanding driving laws and being able to spend the currency you already have are indeed features.
- Culebra has amazing beaches - Visit the bioluminescent bay - Visit El Yunque. You can do the regular tour or visit other trails. - You can go rapeling - You can go SCUBA diving - You can go visit reefs - You can go zip-lining
They're not limited to PR, but you can do them someplace new/different.
You can escape the cold. (45° here and raining. I _kind_ of wish I was back in PR)