Since Gokaiger-Earth is basically All Sentai Canon Exists Here, I presume it has continuously been in danger of being destroyed for large portions or all of everyone's lives. So Gai's enthusiasm might be a little weird. Like being a die-hard fan of freedom fighter groups. It's normal to support and cheer for them, but it'd be weird to know them all by name and appearance and bloodtype or whatever. I'm not sure if I'm making much sense.

Sending him to a therapist too, maybe? That could be pretty hilarious.