(BANG) -Penelope Cruz ''worries less'' since becoming a mother.

The 'To Rome With Love' actress has ''always loved to worry'' about everything in her life, but since giving birth to her 17-month-old son Leonardo - her only child with husband Javier Bardem - the brunette beauty isn't concerned about meaningless aspects of her life that used to bother her before parenthood.

She said: ''For me, having my son means I worry less. I've always loved to worry - ever since I was a little girl people would tell me I worry too much. But these days I really have to pick my subjects to worry about because there are only so many hours in the day.

''You have less ego because you are not number one any more. The things you used to believe were important - such as what people think of you, whether they like you - you realise they are not so important, not really.''

The 38-year-old star insists becoming as mom has ''changed'' her for the better, despite admitting she constantly feels tired due to the demands that come with having a baby.

Speaking to the UK edition of HELLO! magazine, she added: ''Now, if you ask me if I am rested, I will say no, because I am not - I am tired all the time. But happy? Absolutely. I feel very calm, very focused, very much in a good place.

''Becoming a mother changed everything for me. As a woman it is the most wonderful thing that can happen to you because it alters the way you see the world. It is such a fascinating and beautiful process.''