The Norse followed the system of primogeniture, in which the family's fortunes went to the eldest son. So, the only route for the younger sons of a Norseman to gain wealth and fame and land was to go elsewhere. Thus, the drive to expand was fueled by the need for fame and wealth. Not surprisingly, the Norse pagan religion shaped the people's daily lives. Two beliefs of a Norseman were especially significant in propelling the Norse expansion.
Death is the end for all but a few.
And they include oath breakers, thieves, and the like who, after death, were taken to Niflheim for torment. Since there was no afterlife, the only thing that survived after death was one's reputation. Norsemen risked everything to gain and protect their good name. It was their stock in trade, and the currency that permitted one to advance in status. Without fame, the broad knowledge that heroic deeds had been performed, a Norseman could not advance.