James Croll left school at the age of 13 years, yet while a janitor in Glasgow he published a landmark paper on astronomically-related climate change, claimed as ‘the most important discovery in paleoclimatology’, and which brought him to the attention of Charles Darwin, William Thomson and John Tyndall, amongst others. By 1867 he was persuaded to become Secretary and Accountant of the newly established Geological Survey of Scotland in Edinburgh, and a year after the appearance of his keynote volume Climate and time in 1875, he was lauded with an honorary doctorate from Scotland's oldest university, Fellowship of the Royal Society of London and Honorary Membership of the New York Academy of Sciences. Using a range of archival and published sources, this paper explores aspects of his ‘journey’ and the background to the award of these major accolades. It also discusses why he never became a Fellow of his national academy, the Royal Society of Edinburgh. In the world of 19th-Century science, Croll was not unusual in being both an autodidact and of humble origins, nor was he lacking in support for his endeavours. It is possible that a combination of Croll's modesty and innovative genius fostered advancement, though this did not hinder a willingness to engage in vigorous argument.