I think scientists need to have a passion for their work, patience for lab work that can be tedious and slow at times, and perseverance to keep going when things go wrong. Science is as much about failure as it is about success. Not all your experiments work, but you learn from them and go on. The up side is that science allows you to be creative, to be a free thinker, and to set your own schedule to a certain extent. You never know where your research will take you.
Science is unpredictable.