expression, na-adjective, noun which may take the genitive case particle 'no', noun
perfectly normal; absolutely commonplace; taken for granted
Emphasizes that something is so ordinary or expected that it is not even noticed. Often used to describe things that are considered natural or obvious in a given context.
For him, jogging every morning is a perfectly normal thing.
In this region, snow in winter is absolutely commonplace.
Her kindness is taken for granted, and no one thanks her especially.
Standard spelling using hiragana for ごく and kanji for 当たり前.
Kanji spelling for ごく; less common but still seen.
Combination of the adverb ごく (極, 'extremely') and the adjectival noun 当たり前 ('natural', 'obvious'). The phrase is a straightforward emphatic form.