how did mindfulness aid the Buddha
Buddha used mindfulness (awareness of emotions and why they arise) as a preliminary to meditation, scrutinising behaviours at every moment of the day, noting feelings and sensations, sensual desires, what caused them, how long they lasted and the sheer amount of them that plagued him in such short periods of time
this wasn't to punish himself but to recognise what was useful for attaining Nirvana and what wasn't, e.g. guilt is unhelpful as it fuels the ego and also to become acquainted with himself in order to exploit his capacities, to work with it and not against it, not punishing himself for natural habits
this wasn't about preventing negative emotion but recognising it and letting it pass
he realised suffering comes from within, from our desires as they prevent us from being satisfied with the present meaning we're constantly discontent but also that everything is impermanent so we shouldn't hold onto these negative desires and thoughts - we can't suppress them but we can choose not to act on them
cravings go in cycles and this compulsion of desire consumes us