All entities who get dissoziated into the universe get an irresistible urge to reunite. Their capabilities to reunite are restricted to a subset of the IDEA-continuum.
Expansion of their knowledge about this subset is their goal in live. Their urge drives them in this direction without knowing the precise goal.
In case of the very first UR-entities (photons?), the subset is the 3-dimensional space and they are restricted to a limited span, they can approach others at once. Else free to decide.