Even as Njenga pursued education back in Central Kenya, he later joined his parents when they moved to Elburgon and settled in Marioson Forest in 1944.

Now considered a full grown man, equipped with some formal education and eager to fend for himself, Njenga decided to start his life and moved back to Rift Valley closer to his parents.

In his memoir, he asserts that his enterprising endeavors resulted in the displacement of the school tuck shop, causing its eventual cessation of operations.

Notably, prior to commencing his duties, he attended a rally wherein a fervent discussion ensued between the white farm owners and the workers.

In the midst of this impassioned debate, Njenga posed a question that significantly displeased the white individuals present, ultimately leading to the termination of his employment.

He had asked his friend the late John Njenga to join him, but he flatly refused claiming that it is dirty work and he is too educated to do such business.

Later Castle Brewing Kenya Limited, a Kenyan subsidiary of South African Breweries (SAB) was formed, with Karume appointed its director.

Attorney-General Charles Njonjo charged Karume and other leader of the movement with treason, as "they had imagined the death of the sitting president", which was forbidden by the Penal Code.

[7] At the National Delegates Conference in Kasarani in mid-1991 Karume moved a motion to repeal Section 2A of the Kenyan Constitution – that is, restoration of the multi-party system.

At the 1992 elections Karume ran on a DP ticket, but lost his seat to Kamau Icharia of FORD–Asili, whose presidential candidate Kenneth Matiba enjoyed higher popularity in his constituency.

[1] At the 2007 election he represented the PNU coalition led by President Kibaki, but lost the seat to Stanley Munga Githunguri of KANU.

Margaret Ndete his sister and who owns a successful chain of supermarkets, named Kamindi Selfridges, James Raymond Njenga who is his cousin and a retired businessman, his oldest living son Henry Waireri Karume who is a successful entrepreneur in the construction and supplies business, Kungu Gatabaki a long time friend and is currently a chairman for Letshego he also appointed his Wife Grace Njoki Njenga as an overseer over his trust.

Investment News Kenya, 14 December 2009: For Kenyan Business Tycoon, Njenga Karume, Honesty Starts Right on the Cover of his Biography