There is very little actually known about Stockmann's past, but it appears he was in the North for a time and experienced poverty. Catherine alludes to the difficulty of those years, and Peter talks about how he helped Stockmann out. Stockmann, though, refers to this time with pleasure and nostalgia, touting it as a time of purity and resolve. His interpretation of events is a manifestation of his innate tendency to only see things from a certain light -usually a more positive light -and ignore some of the actual duress of the situation. It is telling that Stockmann thinks of the time fondly and Catherine does not, for the contemporary events are quite similiar.