micromania
/mɪk.roʊˈmæn.ɪ.ə/Definitions
1. noun
A state of being obsessed with small objects or details.
“The collector’s micromania for rare coins led him to spend all his savings on a single coin.”
2. noun
An excessive or unreasonable enthusiasm for something, especially a hobby or interest.
“The artist’s micromania for painting watercolors led her to spend all her free time creating new pieces.”