If he told you then work on your trust relationship. If not, then that's a serious red flag and I'd suggest cooling off the relationship for a while.
The only thing I can think of is that he assumed you would think he was a better and/or more interesting person if he was 33 instead of 28. There may be other reasons, perhaps he is an identity thief and forgot which identity he was using. But odds are he was just trying to impress you in his own way.
There are alot of women who like to date an older man. 5 years is not much older but then again I know women who like to date men 2-7 yrs older than themselves. Maybe he was going on this information.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.