I think that this is about how a person may have different groups of people that he knows, and with every group he is a different person, but never himself. It could even be that to be around people he admires he had to do drugs to fit in and is now hooked. So he looks upon this and feels foolish because, despite the high he gets, the drugs make him feel terrible, because that's not him, he did it to fit in and can't stop, and feels stupid and lonely.
I think that this is about how a person may have different groups of people that he knows, and with every group he is a different person, but never himself. It could even be that to be around people he admires he had to do drugs to fit in and is now hooked. So he looks upon this and feels foolish because, despite the high he gets, the drugs make him feel terrible, because that's not him, he did it to fit in and can't stop, and feels stupid and lonely.