Sentence:  I felt superior to the neighborhood friends I was leaving behind , felt <WSD>older</WSD> than my years , and was full of compliments for myself as I headed into the subway that was carrying its packs of passengers out of that dull borough and into the unstable , tantalizing excitement of Manhattan . 
Meaning of the word marked with <WSD> tags:  (used especially of persons) having lived for a relatively long time or attained a specific age