I've always wanted to be able to whistle really loudly (you know, the one where you use your two little fingers!) My mum's often shown me how to do it, but still I can't. Is it something that some people can do and others can't, or can everyone do it with practise?
If you practise a lot then you should get better but its one if those things that some people better at doing than others. I, like you, can't do it all but my Mother can.