I wouldn't say I'm a spender in the sense that I'm going out on huge spending sprees. However, to be able to function at the top of your game on the professional tennis circuit often requires an element of frequent spending.

Every week I'll be spending money on flights, accommodation, stringing and even things as simple as taxis, meals out and, of course, paying the other members of my team. I'm still very careful, though, with what I'm spending.

I've had an entrepreneurial mindset from a young age and I've been interested in companies and products that are a little bit different.

I didn't practise it loads when I was at the academy in Spain, but when I got on the ATP Tour it's something I dedicated a lot of time to.

Since there are a wide range of entrepreneurs fundraising at any given time, I looked at each opportunity as it has arisen and on its own merits. Then I've sat down with my financial advisers, we've looked at the numbers and gone for the businesses I believe have real potential.

I'm not allowed to make a joke. It is a bit unfair how I'm treated. I thought it was a joke. I got calls and messages. I would rather not to have to worry about things like that. It is disappointing.

I'm definitely open to change, but at the same time I am quite stubborn.