Jews in America always say that "He who, when young, is not a liberal has no heart; he who, when old, is not a conservative, has no head." They're all morons too, I suppose. That's okay. Evolution still happens, whether or not one chooses to accept its results.
Pretty sure that commonplace is neither Jewish, nor accurate.
Technically, the Jewish version, of course, is "He who, when young, is not a liberal has no heart; he who, when old, is not a conservative, has no money." As to its accuracy, I suppose that If you're pretty sure about something, then it must be so.
Well, I've heard that chestnut dozens upon dozens of times, and never before has it specifically been related as a Jewish saying, or having anything like a "Jewish version". As for its accuracy, the actual political scientists are pretty unanimous in saying that peoples' political views tend to solidify in early adulthood and by and large don't really change when they get older.
To be fair, it's one of those chestnuts whose provenance and accuracy are entirely beside the point, though the murkiness of both kind of makes me question the wisdom of anyone who passes it on.
I don't remember where I saw it (maybe reddit?), but someone said it was "liberal vs. conservative" in the 1800s European monarchy sense, and "liberal" should be "republican"(as in supporting a republican form of government over the monarchy).
But idk man.