Senku appreciated the response to his hypothetical response and let out a genuine laugh, not at Gladio, but because that to him was so nonsensical, and therefore it amused him.

"Of course there's more than that in a river! If there's fish, they must have a source of some kind of food, and definitely you have to think about the river basin, where you can find all kinds of interesting sand and rocks."

The concept of privacy seemed pretty far away. He got moments time to time, but they were certainly short and always interrupted eventually. He also shared space with one of two other guys so it wasn't like he had his own room anymore. Now, on the train, he had roommates again.

"Yeah, off the top of my head I'm looking for some rocks that I can repurpose into some tools, because I've got nothing, and then I want to explore and see if I can find any minerals, and it's a beach so maybe some shells? I'd look for quartz sand but since I can't actually get a forge going in the short period of time we're here, that won't be helpful." He was speaking in some kind of stream of consciousness here, but at the introduction and the offer of the handshake he accepted.

"Ishigami Senku. Senku's fine." He said with a bit of a dismissive wave at his full name, but he did have manners at least.