I go to Hawaii every couple of years. A few years ago, I went on a bird walk i with Jack Jeffrey, a well-known birder specializing in endemic Hawaiian birds. I was the only novice on this hike and thank goodness for the others who could spot all the birds that I hoped to see. The i'iwi is my favorite also - and we did see it, along with many of the beautiful tiny birds that can only survive in the higher elevations now, due to non-native predators including mosquitoes.
I have a lovely path near my home that I can walk to in 7 minutes or so (I live in western Massachusetts). It is a raised path between two wetland, swampy areas so there are always birds to be heard and seen. Yesterday I saw a very small bird that I didn't recognize. It jumped along the ground and in bushes near me for quite a while, as I stood. I was able to observe the beak, which was thin and a bit long, but not curved at all. I had been thinking that maybe it was a Carolina Wren but the beak was not right for that. When I got home, I looked in my bird app and it may have been a Ruby-crowned kinglet. Maybe...