This famous quote is famous due to Alfred Korzybski (1879-1950) who coined it. Its always important to use sources that may be a bit, say, more rigorous. Research in many areas illustrates that memory is especially complicated and affected by far more variables than age, emotion, or "anchors."
Some of the important variables are molecular. contextual, semantic, episodic, interference, reinforcers, phisiological, dietary, relevance, coding, perception, redundance, and the list goes on and on. I am trying to just use variables that can be related simply in just one word...but that leaves out a lot of highly important stuff that would take some short sentences! You may want to investigate some good research and summaries on the memory.
So, it is not possible to provide a simple answer to your question.