I have no idea who told you this information, but it's totally untrue. Plant Biology is, at this level, an absolute science. There are no mysteries left involving the cloning of plants. The cloned plants are at the same stage of development as the host plant was at the time of the cutting.
A plant "knows" years passing ONLY by the cycles of light. No other variables make a bit of difference. A plant that is kept in perpetual vegetative growth, will NEVER die, as long as a 24/7 light with no stress and proper nutrients are delivered to it. No stress covers a lot of things; water stress, light stress, physical plant stress, nutrient stress and temperature stress, among many others.
If I could suggest some reading to you, any book that covers plant biology will teach you many, many things that are common among plants in the biological sense. For specific information on the biology of Marijuana, there are lots of them out there too. Surprisingly, many are available online, through the big book sellers like "Barnes and Nobles".
Good luck to you man!