Okay, I will answer my own question to summarize some things:
- You're automatically subscribing discussions at your own changesets since the new feature was introduced (November 2nd, 2014)
- Currently you're not subscribing to your own changesets that were made before that date (there is a [ticket on GitHub][1])
- Unsubscribing and Resubscribing to my own changesets is possible
- If you're commenting you're automatically subscribing to a discussion (although you previously may have unsubscribed)
[1]: https://github.com/openstreetmap/openstreetmap-website/issues/827https://github.com/openstreetmap/openstreetmap-website/issues/823