The best advice I got from an old guy at work when I was young was "start putting 100 dollars extra into your super every pay" (old man wished he'd looked into saving for retirement a lot sooner), the worst was "save yourself some trouble and go find a woman you hate and buy her a house" (old man whose marriage was based on him not being there and which immediately broke down when he stopped working away and wished he'd never bothered with it).