What have I done to my board, and how do I get my cards back?

[Nathan Mann]

I was trying to type a card and hit some unknown combination of keys that seemed to remove all the cards from my board.  But even though the cards aren't there, I can still see them listed as per the attached image.

Can someone please explain what's going on here and how I can get my cards back?

Thanks.

[Nathan Mann · Accepted solution]

[Nathan Mann]

Looks like I've found out what happened. I guess I applied some filters by mistake. Once I disabled the filters in the top right, I could see all my cards again. 

Might leave this post here for when someone else has the same problem.