I read an interesting one on Reddit a while back. I'll quote it here:
I had a lucid dream, in which everything around me was in a constant state of folding in on itself, and revealing hidden symmetry that was not apparent at first glance. For example, if I were to look at another person they would become highlighted as if to gain my attention, and then fold along a vertical line pointing out the bilaterally symmetric nature of the human form. When I awoke I discovered that my perception of the world around me was fundamentally altered to see in terms of how symmetrical things were.
More specifically, I could create Ambigrams almost instantly when given a word, or multiple words combinations (Wiki: An ambigram is a typographical design or art form that may be read as one or more words not only in its form as presented, but also from another viewpoint, direction, or orientation). The first one I did was a variant of the word "Shampoo", to read as "Conditioner" when flipped over http://i.imgur.com/VCGwK.png (Long story on why it was those words, but my friend had been trying to do this task for quite a long time). I did not premeditate its creation, and essentially wrote it down without lifting my pen from the paper. I have dozens more that I created, in vastly different styles, that I would be willing to share.
This new ability persisted for about 1 month, before it started to fade. I'm still very skilled at creating ambigrams but felt that for that one month time I was positively brilliant at their execution. After some research the only story I could find that was similar to mine, is a case study presented in a book called "The man who mistook his wife for a hat", about a patient who dreams that he is a dog, and awakes to find that he has a heightened sense of smell.
Thought I would post some of the ambigrams here that I did as requests for fellow redditors.
http://i.imgur.com/mN7z5.png (Ninjas vs. Pirates)