Definitely!!! Being a scientist means that you are often working on things that noone else has ever done before – and that means you sometimes have no idea whether you’re doing things right, or what the results are going to be!
I also sometimes worry that I’m not good enough to be a scientist! In fact I worry about that quite a lot. When a project goes well, or I find out something that can help people, it makes it all worthwhile though. I also think that now I’ve spent so long doing training, it would be a real waste not to spend my time trying to use what I’ve learnt to help people.