A related and important skill is keeping in touch. Most people are really bad at keeping in touch, especially without a structure like university that keeps you in frequent contact. This means that many friendships fizzle without this structure. And this is really sad! I find a common mindset is ‘if friend X really valued this friendship, I wouldn’t be the one to always reach out’. But, empirically, I am confident many of my friends value our friendship, but also suck at reaching out. Being conscientious and organised is just hard