The Take That star - who is married to US actress Ayda Field - is hopeful of starting a family in the near future and says impending parenthood is the reason he has taken control of his life and become more comfortable with appearing on stage and socialising with others.
Robbie - who famously suffers from crippling stage fright - said: "I`m going to be a dad- maybe next year or the year after and I don`t want their dad to be emotionally inept, for my own well-being as well as theirs.
"At the start of the year, I got a feeling that `things` can be different. It started as an ember and now because of the tour it`s a furnace.
"In fact it started when we - as a couple - were kindly invited on holiday that was a once in a lifetime thing but it involved going with people we didn`t know. My automatic reaction normally would have been, `No, be safe, don`t step out of your comfort zone` but then I thought of the kids we`re yet to have and said, `No f**k it, I want their dad to be able to do this sort of thing.` So I did. Things just snowballed from there."
As well as wanting to have children, Robbie - who has numerous tattoos - is also planning more body art.
He added on his official blog: I`m having a Keith Haring picture for my next tat and then I want Archangel Michael."