I don't know if just going to nature is sufficient to get fascinated with biology. In my opinion it takes a fundamental reset in how you think about anything you see. Humans while smart have obviously had to learn to "ignore" thinking about how things work. You don't think too hard about how anything works really. I mean at a cursory level sure, but by vastly different interpretations of the word "cursory", you can change your thirst to know how things you see work at more and more fundamental levels.

You don't need to go into nature to get this curiosity except for the possibility that it makes you more meditative. You can look at your arm and think what the hell happens in there at a molecular level to make you move the muscles. Or when someone says nerves conduct electricity what the hell does that mean?

I revisit this feynman video of him explaining (or not) magnets every few months and I think it's relevant to this question. https://youtu.be/MO0r930Sn_8?si=CkWYfiGoGCgAANwP

When I think like that I'm just curious why OP and others blame teachers or whoever else for not inducting the curiosity in them. Like it's someone else's job to make you curious? In my opinion you're either born that way or you're not. Some airport store book isn't gonna make you the next whatever scientist you adulate.

I sometimes skywatch late at night, marveling at the vastness of what's out there, and the glimpse of it we get over here. That gives me a sense of wonder about space, but did not make astronomy any more appealing to me.

Gaining an appreciation for nature is good, getting fascinated with biology is also good, but one is not necessarily related to the other in practice.