Early humans had to fend for themselves (and the other members of the bands they belonged to) in a hostile world full of uncertainty and danger, which belief in them could only exacerbate. As soon as sentient beings - hardly even people at the time - had the intelligence to recognize their own wants in any other way than mere instinct, they wished for their wants to be satisfied - preferably without having to do any work or without any conditions being required.
Spellwishing: Thus the most primitive form of magic was born: spellwishing, the belief that one can alter reality simply by wishing it. The way is so primitive, one would not even recognize that what they were doing to beget it was magic at all. But spellwishing is also the least likely to succeed, because it diametrically opposes the ingrained idea that reality is reality and one cannot simply believe it to be any other way and have it be so. Coupled with the fact that no other magic had ever been witnessed (since spellwishing is the earliest way), only one in millions would be successful. Considering that in those early times the total human population was in the 1000’s, 10,000’s and then 100,000’s, a spellwisher would only appear once in many generations. As it is so rare, pure spellwishing is the only form of magic that did not have institutions rise up around it, and almost always did not have staying power, lasting for only one incidence.
Spellwilling: The desire to have one’s needs fulfilled gave rise to another form of magic, spellwilling: the belief that one can alter reality simply by ‘willing’ it. This approach is superior to spellwishing because of several reasons: 1) the internal locus of control - a belief in one’s own magical potential, as opposed to external locus of control, results in a greater chance of success; 2) the use of a ‘triggering moment’ as a distinct break in reality by which an alteration may begin, which also results in a greater chance of success compared to spellwishing which lacks this moment. Compared to spellwishing, spellwilling, by focusing on the internal locus and thus ostensibly caring less about chance, meant that a successful spellwiller could go on to work additional magic - resulting in the first reproducible magic. Pure spellwilling is the second rarest form, with one in tens of thousands being successful. While there were very small orders of spellwillers, the vast majority of these were wilders.