Imagination
Science can be an extremely precise discipline: you need to measure everything as accurately as possible, to meticulously note things down, and, if required, to process results according to previously agreed upon, fixed rules. At the same time, however, scientists require a healthy dose of creativity. They have to come up with hypotheses and theories, as well as experiments with which they can test their ideas.
Unfortunately, that creative aspect is often ignored, even though it is actually the driving force behind all scientific progress: You need a nimble mind, and a lot of imagination. In the end, you need to think of something no one has ever thought of before.
You can stimulate creativity by opening yourself up to new information, or by exposing yourself to a new work environment. Therefore, cross-fertilisations between various scientific disciplines, or between science and other fields, e.g. the arts, are extremely prolific.