Einlion
The closest I came to something similar to what Neko-girl describes happened on two occasions. The first was when I was with the girl I liked and we went on the roller coaster for the first time. I felt incredibly light, scared and happy that I was shouting, not as loud as possible, but more than normal. Once again, it was when I was going through the seventh round (maturbat), I felt a murmur in my heart and everything started to darken (the vision) but I didn't stop until it was all over, at which point the one I realized wasn't breathing.