Age Discrepency

I have seen this movie many times, so I am surprise I did not notice this until now. The movie takes place in 1963, roughly 18 years after the end of WWII. Salomon Tauber is portrayed in the flashbacks as a relatively young man, perhaps in his late 20's or early 30's. Yet, 18 years later, he is depicted as a man in his 60's or even 70's. I realize a concentration camp would have aged him beyond his years, but even when you take that under consideration, it doesn't seem to add up. Any thoughts on this?