"I think I grew a grey watching you procrastinate"

This quote by Brandon Boyd is a metaphor for the sensation of aggravation and vulnerability that can come from viewing someone procrastinate. It suggests that the speaker has been enjoying the individual hesitate for so long that it has triggered them to age prematurely, as if a grey hair has actually outgrown their head. This might be analyzed as an indication of the speaker's exasperation with the individual's procrastination, as if they have actually been awaiting them to act for so long that it has taken a toll on them. It could also be interpreted as an indication of the speaker's concern for the person, as if they are stressed that the individual's procrastination will result in negative repercussions. In either case, the quote conveys a strong emotion of disappointment and helplessness.