While at Aarhus, he received Statens Uddannelsesstøtte, a state education grant that provides Danish university students with a stipend to cover living expenses while enrolled.
Even after completing his degrees, Fisker continued to live on a budget corresponding to the SU stipend he received as an undergraduate[7] although his income increased over time.
He considered himself retired when he left his astrophysics career in 2009 at the age of 33,[4] having accumulated a net worth 25 times his annual expenses of about $7,000.
[4] In further developing the Early Retirement Extreme concept, Fisker used the ERE acronym to capture a more refined philosophy that further de-couples personal resilience from financial concerns: he termed this Emergent Renaissance Ecology.
[11] This built on his ideas about the 'Renaissance Man' as introduced in the Early Retirement Extreme book, focusing on re-skilling and understanding emergent societal systems.