The term 精通 (jīngtōng) reflects a deep-seated cultural value in China: the respect for dedication, depth of knowledge, and true mastery. This is closely related to the modern concept of 工匠精神 (gōngjiàng jīngshén), or the “artisan spirit,” which praises meticulous craftsmanship and the pursuit of perfection over a long period. To a Western learner, 精通 (jīngtōng) might seem equivalent to “being an expert” or “mastering a skill.” While similar, there's a subtle cultural nuance. In the West, particularly in American culture, there is often praise for being a “jack-of-all-trades” or having a broad skillset. 精通, however, is firmly focused on depth over breadth. Furthermore, due to the value placed on humility, it is considered boastful for a person to claim they are 精通 in a subject themselves. It is a level of praise more often bestowed upon others. Aspiring to 精通 a skill is a noble goal, but claiming you have already arrived can be seen as arrogant unless your skill is truly undeniable and recognized by others.
精通 is most often used in formal and professional contexts.
You would not use it for simple, everyday tasks. For instance, you wouldn't say you are `精通` cooking instant noodles.