Same here. I went to alton towers with some mates, and they made me promise not to wear my collar; I didn't and immediately regretted it; as we arrived I kind of went into panic mode, which wasn't helped by the extreme roller-coaster I picked as my first. When I got off, I staggered off it in tears, and next thing I know, I am surrounded by a ring of my mates bent over me with concern in their faces; apparently I hyperventilated until I fainted. A nearby attendant stated that that was the first time he had seen it happen in all his years of working there; he went on to say that he had seen very little as extreme, even for a newbie.
Thus, I believe that the same thing as you, tallice, has set in for me; and far more rapidly than I expected.
Sorry if the anecdote was a little off-topic.