It's an easy enough language to master. There aren't a whole lot of constructs. The difficulty is wrapping your head around the massive lines of code that any COBOL program of reasonable complexity is bound to have. Not to mention every variable being defined by what it looks like, no notion of scope, no syntactic sugar like for or while loops, and no notion of methods. It's all supposed to read like English, but while English can pack a lot of meaning in a few statements, COBOL can't do anything in a few statements.