The Photos app has a new tab in it called "Memories," and it automatically gathers up some of your best moments from certain places and time periods.
Memories is a pretty cool feature for looking back at key points in your life, especially if you have thousands of photos on your phone.
If you click on one of the Memories, it takes you to a photo gallery, while also featuring an automatically-created video (with music) at the top. For my "Best of Last 3 Months" video, for example, it put in photos from all different moments, along with video of my son riding a bike for the first time without training wheels.
That was definitely the best moment. Nice job, Apple.
To access it, just pull up your Photos app and click "Memories."