For Piaget and Vygotsky, the process of equilibration results in subjective knowledge constructions that approximate some external objective reality. Taking the work of his predecessors a step further, German-born philosopher Ernst von Glasersfeld proposed that objective reality does not exist. In other words, he proposed that subjective knowledge constructions are the entirety of a person’s reality.
For von Glasersfeld, it is impossible to take knowledge out of its subjective context. “To assess the truth of your knowledge,” he wrote, “you would have to know what you come to know before you come to know it.”
He is not saying necessarily that the capital-T Truth of things does not exist, but that individual people are not in a position to know it. The constructivists say that new knowledge (objective, shared) builds on existing knowledge (subjective, personal.) Von Glasersfeld simply takes that concept to its most radical form: that at their most basic level, human beings grow what they know from a place of subjectivity.
If this makes your head hurt, that’s OK. What’s important here, particularly for educators, is that who people are and how they learn are deeply connected. In practice, standardized curricula do not always take this concept into account. When educators can find ways to connect lessons to individual student experiences, it can help make lessons stick.