Mollison was, and still is, entirely correct with this statement on so many levels. Lets take the statement apart and look at the key words for some better understanding.
Only – to the exclusion of all others
We have many paths that we can take to the future; some lead to greatness, others less so, and some should be avoided altogether. It may sound simple, perhaps even sensible, but it makes no sense to take paths that lead to outcomes other than positive, and hopefully great. And yet we too often take those paths to our ultimate regret. So we need to keep reminding ourselves, that the ONLY paths to take should be to positive outcomes, and maybe some that are great.