English version

at heart

From Longman Dictionary of Contemporary Englishat heartat heartCHARACTER/PERSONALITYif you are a particular kind of person at heart, that is the kind of person that you really are even though you may appear or behave differently He may be a working class boy at heart, but his lifestyle has been transformed. Let’s face it, we’re all romantics at heart. have somebody’s (best) interests at heart at interest1(5), → young at heart at young1(5) heart
Examples from the Corpus
at heartPaul was an easy-going fellow at heart who wanted only to enjoy himself.I guess I'm just a kid at heart.She's a traveller at heart. You'll never get her to settle down.