oh.. i dunno.. maybe because someone in their late 70s/80s with severe schizophrenia needs to take a break once in a while? 
Can you find one shred of evidence to support that? Any report at all that he was tired or having difficulty during those periods?
Well, this video was published in 2015... I'm not sure when he spoke but you may have a point, in this video he looks in tip-top physical condition (crossfit maybe?)
https://www.youtube.com/watch?v=NUyCO3FXHS4
"The Bitcoin might not be it.. but.. if you had gold which is a step towards honesty or silver.. silver.. if you had silver... that was argent..in French.. it becomes intrinsically honest.." -John Nash
Did Nash also collaborate with Coblee on Litecoin ("Silver to bitcoin's gold") ?!?
("more complex ideas") 
http://www.coindesk.com/litecoin-silver-bitcoins-gold/
John Nash died on May 23rd, 2015 with litecoin near an all time low, still under $2. Note that his death occurred literally days before one of the biggest pumps in litecoin's history when it peaked over $8 during the following weeks
