After retiring, he recaptured the happiness of his childhood through painting.

recaptured 是动词 recapture 的过去式形式。recapture 由前缀 re-（表示"重新"）和 capture（"捕捉、获得"）组成，字面意思是"重新获得"，引申为"重新找回、重温"的意思。