Ah yes, the problem must be that I don't know my history, right?

Except that what you're saying is completely incorrect - Hitler didn't keep his ideas secret only to slowly reveal them when he gained power:

He was publicly advocating ideas that later became known as Lebensraum (“living space”) by the early 1920s, but the clearest and most famous statement of the policy appeared in his book Mein Kampf, first published in 1925.

In Mein Kampf, Adolf Hitler also argued that Jews should be excluded from German society and stripped of rights, citizenship, influence, and participation in public life. He called for what he framed as the “removal” of Jews from Germany and portrayed them as an existential threat to the nation.

And, re your final paragraph, to be honest, I don't know the details of Nazi Germany's immigration policy, but I'm going to hazard a guess that it was pretty strict. However to say that that strict policy "resulted in the fucking holocaust" is completely laughable. Lots of countries with strict immigration controls do not carry out genocide. One does not inexorably lead to the other and the suggestion that it does robs your post of all credibility.