I drove in rural Southeastern Ohio years ago on a regular basis, and the only radio options were farm-related stock exchange rates and religion - so I listened to the religious program. There was a Protestant minister who regularly preached openly about "Mormon cultists" and mentioned occasionally that nothing good ever comes from such devilish sources. Most of what he preached was stuff with which I disagreed, but some of it was inspired and made me think about and see some things in a new light - for which I was grateful. At the risk of sounding dismissive (which I don't want to have happen), I had to sort through a lot of what I saw as doctrinal garbage to find the pearls of wisdom - but I really enjoyed the beautiful pearls when he presented them.
I had to laugh one day as I heard him tell his listeners about a wonderful idea that James Hobson (Focus on the Family) had been inspired to teach. It encouraged Christians to set aside one evening each week to spend with their families - to share the Gospel, testify and engage in fun activities in order to strengthen the family and bring Christians closer to God. He said it obviously was prophecy for our time, and he thanked God for inspiring Hobson in such a manner - and he had no clue whatsoever that the idea was modeled after the Mormon program of Family Home Evening.
We certainly can learn things from others, but they certainly can learn things from us - even if they can't attribute those things to us.