Why would Prince Charles be in a hurry to be King?

I wonder why everybody, including those very clever clogs at Private Eye, thinks that Prince Charles is in such a hurry to be King?  He now has the freedom to do all the useful things he does do, above all at the Prince's Trust, which has substantially helped 650,000 young people over the 35 years of its existence.  As is evident from all the publicity there has been about the Queen's life recently, a whole lot of it is spent doing her duty, which involves endless handshaking and being the figurehead for the Country and the Commonwealth.  The Prince probably observes her doing a very good job and appreciates all the more his present ability to do what he is most interested in.  Being the Monarch doesn't seem to me a very pleasant task at all.  Thank goodness the Queen can still perform it so well - and thank you to her.