Context #1

Two colleagues are talking at work…

Penny: How are you finding the transition from accounting to account management?
Mark: It’s all quite difficult and confusing. I am never sure just what it is I should be doing.
Penny: It’s natural to feel like a fish out of water for the first few weeks. You’ll settle in no time.

Context #2

Two friends are talking …

Ana: How’s school going?
Mike: I’m feeling a little like a fish out of water.
Ana: Why is that?
Mike: Well, after spending twenty years in the workforce, going to school with a bunch of bright, quick young people makes me feel out of place. I’m not sure I can manage the workload.

Meaning: To feel “like a fish out of water” means to feel awkward because you are in a situation that you have not experienced before or because you are very different from the people around you.

https://languagesystems.edu/