What is "it's never too late to mend"

prov. You're never too old to change your ways. Learning is always possible.

It's Never Too Late to Mend (US release title Never Too Late) is a 1937 British melodrama film directed by David MacDonald and starring Tod Slaughter, Jack Livesey and Marjorie Taylor. In the film, a villainous squire and Justice of the Peace conspires to have his rival in love arrested on false charges. It is based on the novel It Is Never Too Late to Mend by Charles Reade.