"But what you realise after you've been in the business for a while is that people develop opinions about you that don't have anything to do with your music, they like or dislike you for a million reasons, they like or dislike you for your last record"

Adam Duritz is recommending that when you remain in the music business, individuals will form viewpoints about you that are not always related to your music. Individuals may like or dislike you for a range of factors, such as your personality, your design, or perhaps your last record. This indicates that even if you have actually produced terrific music, people might still not like you for other reasons. Duritz is warning that in the music service, it is very important to be aware that individuals may form opinions about you that have absolutely nothing to do with your music. It is important to be knowledgeable about this and to not take it personally.