To find your own favorite past songs of the summer, visit the Home screen of the Spotify iOS or Android app, or simply log onto Spotify's website. If you've been a subscriber for at least a year, you'll be treated to your own personalized playlist. Mine is accurate, yet predictably embarrassing, populated by artists such as Shakira, U2 and (thankfully) MS MR. Spotify knows my mostly terrible music tastes haven't matured much since high school.
You can also share tracks from your personalized summer playlist with your friends. If you receive Spotify emails, you will be sent your top three summer songs on a shareable card that you can then send to friends or post on Instagram. If you receive such a card, open Spotify, select the camera icon and scan the card to listen to your friend's top songs.
If you haven't had an account long enough to have your own playlist, you can also listen to the new 50 Years of Songs of the Summer playlist. It includes every top song of the summer from 1967 to 2017, based on Billboard data. It's probably a good thing that earworm isn't actually fatal, because otherwise this playlist might kill you.