The 'Blurred Lines' hitmaker has been married to the '2 Guns' actress for eight years and credits his spouse for being his ''rock'' throughout their relationship.
He gushed: ''I don't know if I would still be alive in some ways if it wasn't for Paula. She's been my rock, my muse, my inspiration and I love her. The whole way.''
Paula, 37, is just as smitten with her singer husband, revealing that they get each other through tough times.
She said: ''I've been there for his down moments and he's been there for mine. Life is full of peaks and valleys. Robin has always been a great person to remind me to celebrate now. Even when it looks like I've got a role but don't know for sure, he's like, 'Let's celebrate!' ''
The celebrity couple - who have a three-year-old son, Julian, together - are ''best friends'' and when they are not working on their respective careers, they enjoy living a quieter life.
Paula added to Prestige Hong Kong Magazine: ''Talking to each other. We watch movies. Just sit and contemplate - we have a house with a bit of a view. Listening to music. Talking about what's going on in our lives.
''We're best friends. We laugh a lot. But that's our down time. We do the things you're supposed to do, like work out - blah, blah, blah, boring, boring. We love to travel together and travel with our child.''
The actress spoke about raising her 11 year old daughter Matilda in the wake of Heath Ledger's death eight years ago.