Does advice from others really matter?

Is it worth it listening to advice from others when you already have your heart set on something & you feel content with the decisions you have made? I confide in talking to my friends about things that happen in my life & unfortunately they don't like a guy that I've been messing with & so they always shut me out & tell me to leave him alone. Granted that they only have my best interest at heart, but at the same time I'm going to do what makes me happy. They don't live my life or feel how I feel. If I'm happy then so be it right? At what point do I draw he line? A friend can make all the assumptions they want, but they truly don't understand the situation no matter how much or how in detail I try to explain it to them. Do I just say fuck it? Or keep an ear open for their advice and be cautious of the things I do moving forward?