It's the same phenomena as when your parents try to give you good advice but you will only listen to it if it comes from the mouths of "outsiders".

Example: my boyfriend tried to get me into Tool for ages and I was very indifferent to it. Then my closest colleague starts playing Tool at work and I'm like "omg this music is awesome" and I go home and tell my bf about this amazing new band I have gotten into and he just gets so offended like "I literally tried to get you into it for years wtf". We laugh about it sometimes.