Arnold Schwarzenegger hit a milestone in age this weekend -- but he doesn't really wanna talk about that ... instead, he put the focus on his late mother, with a very touching tribute.
The ex-California governor and legendary movie star hit the big 7-5 Saturday, and he's getting tons of tributes online and elsewhere ... with everyone wishing him a happy 75th birthday. Of course, it's well-deserved -- but AS's mind seems to be elsewhere right now.
On Friday -- the day before Arnold's own bday -- he posted a remembrance for his mom, Aurelia, whom he said would've turned 100.