Just the other day, on some random GitHub Issue, I left a comment.
Now I want to find my comment, but unlike Facebook's Activity Log, since the Issue was not created by me, nor do I own the repository, well... the only way to find that activity of mine is to dig through my browser's history (oops, gone), or remember what I was commenting about, and try to search for that subject all over* GitHub Advanced Search is great... if I was the issue originator.
Yes, one one's profile there are one's contributions, but comments on random issues aren't contributions.
I assume I have posted this question to the right Stack Exchange.
*OK, I found it. But how could I have found it if I didn't remember what the content was about. What if all I remembered was it was I who posted a comment a few days ago, but I don't remember what repository or subject etc.?
You can try the following link:
https://github.com/notifications/subscriptions?reason=comment
See also: How can I find all public comments for a Github user?