Someone you like but don't know very well needs some words of wisdom: it might feel awkward to cross that intimacy line with them, but you should give the advice that you know they need to hear. And when you reach out to them, remember to be gentle. Put yourself in their place and you'll know exactly how to say what you need to say. You have a good memory and an even greater sense of empathy, so you are in a position to help them learn from their mistakes better than anyone else.