1. He was pressured into marrying a woman he didn't love, causing pain for everyone involved. Only late in life did he marry his true love.
2. He spent his entire life preparing for one job: King. And his mother refused to abdicate so he could assume the job at an early age.
Elizabeth's own mother abdicated while Elizabeth was still in her 20s. She might have resigned at 50, after a good run. Or at 60. Or 70. But she's still hogging the throne at 95.
Charles was forced to waste his entire life waiting for the throne, as it was his "duty" to wait to be king someday. He wasted much of his life with the wrong woman.
Yes, I feel sorry for him.
So do I. It may sound strange, but I really mean it :-(