it couldn't have been a dream

I had an experience one night that i can not figure out.
One year when i was about 7 years old it was guy fawkes night and i had been to a bonfire at our local cricket club which is about 300 meters away from our house, i was trusted to walk there on my own as my family knew basically everyone who went there.
Anyway this particular evening i was walking home past the rugby field which joins on to the cricket club, i looked through the entrance gates and saw a purple kind of blob with about 3 eyes and huge arms. I was totally in a trance for what seemed like ages but when i snapped out of it was only like 10 mins, the problem is it felt like a dream but i was awake. Has anybody else experienced anything similar? I guess the 'monster' was a part of my imagination but why did i experience this at that point in time?