The first few times Elias ever saw bubbles, he didn't care in the slightest. He was always like "So what?" But then one day a couple weeks ago, I was blowing bubbles with him at home, and it just clicked! He laughed and tried to grab and pop them, and he even said "Bubbles!" very clearly! So here's a video of that day. He has loved them ever since!
If you watch it all the way to the end, you can also see his good use of the sign for "Please," which is pretty new in his signing vocabulary.