Imagine a pond clear of debris and on day one a leaf falls on it, on day two 2 leafs fall on it and with each passing day the number of leaves continues to double. On day 60 the pond is completely covered with leafs.
On what day is the pond half full? Answer: day 59 (I suspect most here are able to figure this out)
Here's a more challenging question, on what day is the pond 1% covered? Answer: day 54
What at first seems like overblown measures makes sense if you understand the exponential grow of pandemics.