The article's headline indicates that actor and comedian Martin Short has spoken about what he considers the single biggest regret of his long career: wishing he had done more with the opportunities available to him. Short, known for decades of work across film, television and stage comedy, is a respected figure whose reflections on his own career carry weight given his extensive body of work.

Unfortunately, the source material provided for this piece consists only of website navigation and header content, with no actual article text detailing what specifically Short regrets or the context in which he made the remark. As such, no further factual details, quotes or examples from the piece can be reliably summarised.