年輪 | 年年齡 8 | Cumulative concept of time, 12
The younger tree is still here, for it is inner part of the present tree.
|This file is licensed under the Creative Commons Attribution 2.0 Generic license. Author: Lawrence Murray from Perth, Australia|
present-self of the tree = younger-self of the tree + the outer layers 
 This is not scientifically accurate. But it is a good analogy for illustrating the cumulative nature of time.
2011.09.11 Sunday (c) All rights reserved by ACHK