To elaborate:

Stage 1: I was taught that crocodiles are the closest living relatives of dinosaurs when I was very young. I was taught that dinosaurs were scaly and cold-blooded, and that crocodiles haven’t changed in hundreds of millions of years, and were the most similar things to dinosaurs alive today.

Stage 2: Later, I learned that, actually, crocodiles had changed quite a bit in the last few hundred million years. Dinosaurs were actually mostly warm-blooded and active, and many were not scaly but instead feathered. At this point I was taught that it was in fact birds, not crocodiles, that are the closest living relatives of dinosaurs.

Stage 3: Finally, I learned that birds are in fact a branch of the dinosaur family tree. Just as humans are not “the closest relatives of mammals” but are ourselves mammals, birds are not “relatives of dinosaurs” but rather a type of dinosaur themselves. The closest living relative of dinosaurs are the the crocodiles—cousins of dinosaurs, but not dinosaurs themselves.