This semester I learned how important it can be to point out to people when they are having fun learning and doing science.
Learning, learning science, especially science class isn't always going to be fun. Sometimes it's going to be frustrating, either for students or for teachers or both, for a variety of reasons. Inquiry, especially, comes in fits and starts. Conversations, debates, presentations are probably going to go on, at times, too long, causing tedium or frustration. There are days that people just seem less excited to talk and to share, and to "dive right in" to science. Hopefully those days aren't too often, but they do happen. Even in a given day, you can hit some slumps or even walls, from which the class may or may not rebound from.
It even varies with students and classes over the years. Some students will be excited about science often. Some students will be excited about science rarely. Some years, there are classes that just click together with their science learning better than others. But with any class and any set of students, there are moments where a whole class becomes excited together about some science thing–a conversation, a puzzle, a phenomena, an experiment, a question, whatever. In these moments, even those students who are rarely excited get wrapped up in the excitement.
I am convinced that pointing out these good times pays big dividends, simply by saying, "I want you to remember this feeling you are having, the feeling you are having talking about science and learning together."
Now, I don't think you should point it out too early, like while the excitement is still building–that might disrupt the "flow" and the "excitement." But I do think it's worth pointing out before the excitement has died down completely, while the feeling of excitement is still palatable. Pointing it out, I think, helps buffer the bad times, because people remember that good times. I think it also helps to build students' identities around science and science learning, because you are pointing to their own emotional capacity to feel good and to get excited about doing and learning science.
Next year, I am going to more deliberately do this. We'll see how it goes.