You grab a cup and bend over to cup some water from the fountain but your grip on the floor below slips and you fall over forward into the fountain. SPLASH! You frantically get upright and drag yourself out of the fountain, not sure how much of the water you ingested with that dive, but it certainly wasn't a bit as even out of the water you spit out a stream of fountain water. You seem almost a foot shorter by now...
Quicker than expected, the world grows huge as you shrink out of any clothes you were wearing and you can't even see over the edge of the fountain anymore. By now, your body has practically lost all muscle mass and body hair, and you have baby smooth skin. In fact...you ARE a baby, about 1 year old. A finger in your mouth reveals you don't even have teeth anymore.
At the best of your ability, you start crawling around for something to cover you as you feel a shiver of cold...your naked body is now more vulnerable than ever, and without any adult abilities you won't be getting far.