when plotted in experience-space, the parametric graph of life is pretty much a spiral, for you often go through similar experiences and phases, just being (hopefully) more knowledgeable every time. growth would therefore happens radially, inwards. in fact, humans do not perceive and measure life over its parameter, time, which might be linear, but across cycles, which of course get shorter and shorter in their way to the center of the spiral, resulting in the familiar feeling that life accelerates continuously.
but this is something I already thought when I was 16. see?