Tl;dr Different people will probably have different answers to the question of how to find the goal & nurture the 'something to protect' feeling, but mine is: your specific working experience is already doing it for you.

What values do other people expect of you?

I think that for many people, their jobs are the most meaningful ways of changing the world (including being a housewife). When you just enter a profession and start sharing your space and time with people who have been in it for a while, you let them shape you, for better or for worse. If the overwhelming majority of bankers are not EA (from the beneficiaries' point of view), it will be hard to be an EA banker. If the overwhelming majority of teachers view the lessons as basically slam dunks (from the students' point of view), it will be hard to be a teacher who revisits past insights with any purpose other than cramming.

So basically, if I want Something to protect, I find a compatible job, observe the people, like something good and hate something bad, and then try to give others like me the chance to do more of the first and less of the second.

I am generalizing from one example... or two...

I've been in a PhD program. I liked being expected to think, being given free advice about some of the possible failures, knowing other people who don't consider solo expeditions too dangerous. I hated being expected to fail, being denied changing my research topic, spending half a day home with a cranky kid and then running to meet someone who wasn't going to show up.

Then I became a lab technician & botany teacher in an out-of-school educational facility. I liked being able to show up later on some days, being treated kindly by a dozen unfamiliar people (even if they speak at classroom volume level), being someone who steps in for a chemistry instructor, finds umbrellas, and gives out books from her own library. I hated the condescending treatment of my subject by other teachers, sudden appointments, keys going missing, questions being recycled in highschool contests, and the feeling of intrusion upon others' well-structured lessons when I just had to add something (everyone took it in stride).

(...I am going to leave the job, because it doesn't pay well enough & I do want to see my kid on weekdays. It let me to identify my StP, though - a vision of what I want from botany education.)

Background and resolution.

When kids here in Ukraine start studying biology (6th-7th Form), they wouldn't have had any physics or chemistry classes, and are at the very start of algebra and geometry curriculum. (Which makes this a good place to introduce the notion of a phenomenon for the first time.) The main thing one can get out of a botany course is, I think, the notion of ordered, sequential, mathematically describable change. The kids have already observed seasonal changes in weather and vegetation, they have words to describe their personal experiences - but this goes unused. Instead, they begin with history of botany (!), proceed to cell structure (!!) and then to bacteriae etc. Life cycle of mosses? Try asking them how long does any particular stage take! It all happens on one page, doesn't it?

There are almost no numbers.

There is, frankly, no need for numbers. Understanding the difference between the flowering and the non-flowering plants doesn't require any. There is almost no use for direct observation, either - even of the simplest things, like what will grow in the infusions of different vegetables after a week on the windowsill. There is no science.

And I don't like this.

I want there to be a book of simple, imperfectly posed problems containing as little words and as many pictures as possible. As in, 'compare the areas of the leaves on Day 1 - Day 15. How does it change? What processes underlie it?' etc. And there should be 10 or more leaves per day, so that the child would see that they don't grow equally fast, and that maybe sometimes, you can't really tell Day 7 from Day 10.

And there would be questions like 'given such gradient of densities of stomata on the poplar's leaves from Height 1 to Height 2, will there be any change in the densities of stomata of the mistletoe plants attached at Height 1 and Height 2? Explain your reasoning.' (Actually, I am unsure about this one. Leaf conductance depends on more than stomatal density...)

Conclusion

...Sorry for so many words. One day, my brain just told me [in the voice of Sponge Bob] that this was what I wanted. Subjectively, it didn't use virtue ethics or conscious decisions or anything, just saw a hole in the world order and squashed plugs into it until one kinda fit.

Has it been like this for you?