When my parents gave me a chemistry set for Christmas, I was close to 10 years old.
Literal
Parents [subject-が] Christmas [at-に] chemistry-experiment set [object-を] gave time, I [topic-は] 10-years-old close age was.
くれた (gave me) is the plain form of くれる — implies the gift benefited the speaker. 10歳近い年齢 (close to 10 years of age) uses 近い (close to) as a modifier. A nostalgic childhood memory with specific detail that makes it memorable.