Christ is true God and true Man... from when?

According to the catholic doctrine, Jesus is "true God and true human." That nature of Him was taken in order to redeem the humanity of sin. My question is: > Since he is God since all times, did he _become_ true human in the incarnation or he was already man before it? If He has became human there, and now He is human also nowadays due to His simple and eternal attributes, excent (indifferent, alien, unaffected, etc) of time and space: **Wouldn't He has to been human since all times since He lives in eternity?**