The actress says her looks were her passport to the world as a young model at 20 ... telling Spanish newspaper El País feeling bad about the hand that fed her won't cut it -- especially cause she's still a massive name decades later at 51.

Sofia says she learned to play to her strengths early on ... after realizing boys started giving her attention and treating her differently.

Though, she says if you're only fixating on her boobs, then that's a you problem ... cause her bubbly personality is behind her longevity in the entertainment business.

Sofia says she's not performing brain surgery ... so the worst someone can do is say she looks ugly and can't act -- which she can stomach and continue moving things along.

She's aware there are women who are younger, prettier, have bigger breasts, and a better figure than her now ... but she ain't sweating it cause she's demonstrated her staying power -- especially with the career risks she takes.

Netflix's upcoming series "Griselda" is one such risk ... the usually glam Sofia morphs into the gritty titular lead -- a real-life story based on the leader of one of the most profitable drug cartels in history.

The shift to such a dramatic role comes on the heels of the huge shift in Sofia's personal life -- she split from Joe Manganiello after 7 years of marriage last year over their differences in wanting kids ... he does, she doesn't.

"Griselda" is already getting early critical acclaim, so it's true what Sofia says ... she ain't solely banking on those good looks anymore; it's her talent that shines.