As it has been pointed out many times, linearity is a construct, an imagined process that has been created in order for strategists and theorists to create easily understandable and logical models.
But it has little root in reality. First of all because reality seldom is absolutely linear, and secondly, the linearity isolates external inference with the process and makes it seem as it happens in a vacuum, when in truth multiple processes happens at the same time intertwined and affecting each other in every direction.
Press “Autoplay” in the lower right corner as you enter the presentation and then “Change constraints” top middle. Absolutly excellent.