That word usually conjures up negative thoughts. Like: "They played like a bunch of amateurs" or something done poorly.
The thing is it doesn't really mean that. It means doing something for the love of it, for pleasure.
My favourite quote about being an amateur comes from an old film... A Christmas Without Snow. i saw it on tv one Christmas season afternoon, while Jeff and i huddled in our room. i was writing what would become my street poems then, and i remember this