Thranduil talking to Legolas in the end

Rating: 8/10 (18 December 2014)

Did Thranduil mention about Aragorn or his father , according to time difference he can't mention Aragorn because Gimli isn't born yet and also there is huge time gap between LOTR 1 and last hobbit movie - if we accept Dwarf and Human aging same time then Aragorn is too old - .
I can't be sure who he mentioned he used strider word so only one we know as Aragorn , please give me correct responses . :(
Update : ( I read some comments created before and I understand Aragorn has elf blood but still he is like 10 years old ?!? )
Last question : Why Saruman wanted to chase Sauron all by himself ,as he was talking to Galadriel about it I felt that he was amused by Sauron's power and his alignment to Sauron started on that moment ?
thanks