Yes, he has. First of all, he spent five years in the British Armed Forces - primarily the Royal Navy where he flew helicopters (rather like both his sons have recently).
Secondly, he runs a number of very successful businesses. The Prince of Wales isn't actually entitled to any personal government funding - instead he gets access to the revenues of lands and businesses belong to the Duchy of Cornwall (he is Duke of Cornwall, as well as Prince of Wales). This includes a lot of farms which people rent from him in the same way they would rent from any other landowner. He's used these revenues to set up companies (most publically visible 'Duchy Originals') that sell food in Waitrose supermarket's and some smaller stores as well all over Britain. He doesn't do a lot of the day to day work - he's more in the CEO role, but it does involve work.
And that's before he carries out the official duties that go with his role as Prince - which actually are a lot of work, when you do hundreds of public engagements a year.
The poor guy has been the longest Heir Apparent in British Royal history.
He is 65 and has been heir since he was 3 — what a task.
He was certainly sound until his middle age years, educated, service in the Navy etcetera. He had a fellow whose name escapes me that was kind of a guru as I recall in the 80s. He seemed to go off on tangents based upon things this guy and his charities would get him involved with.
I have somewhat had to pay attention to him as he and I are almost exactly the same age.
The Queen has done a wonderfully stable job at a tough time for monarchs. I imagine as long as she is able she will not be able to surrender the reins of power.