Psilocybin and other psychedelics may be that exogenous agent, they release Brain-derived neurotrophic factor (BDNF) [0], which plausibly could cause “rewiring of the cerebellum” [1][2], and may even do this with sub-perceptible (micro)doses [3].

[0] https://pubmed.ncbi.nlm.nih.gov/37280397/

[1] https://www.nature.com/articles/s41386-022-01389-z

[2] https://www.frontiersin.org/articles/10.3389/fpsyt.2021.7246...

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8033605/