I've always been incredibly curious about all the life around me but at the age of 35 it finally started to bug me that I had no idea what, for example, the dozens of types of birds around me were called. For the past few months I've started making it a point to identify every single bird that I see around the yard, to spend a few minutes locating a photo of it and listening to its call and reading information about it on Wikipedia. Just in the past few months I've identified over two dozen birds that I grew up seeing and hearing and now I finally know what they're called.
What I'm realizing is that it takes active participation and interest in indentifying things to really learn their names and their histories, not just a passing interest.
The Cornell Lab of Ornithology has a site [1] and an app that is amazing for identifying birds. My favorite feature is how it also lists birds that are similar, which makes it a lot easier to find the specific bird you're looking for. I then compare visual information with the auditory information of the birds calls to make a concrete identification.