When did you last help a colleague succeed and feel enthusiastic about it?

Think about it. It could be an unintentional (or intentional) trap! It may be the intention of the interviewer to see how you handle this question in particular whether you cite an example by saying derogatory or negative things about a colleague that you then have to help out especially if you seem to be demeaning that colleague. Your example should show that you are always able and willing to help a colleague or teammate and enjoy doing so because this contributes towards better performance of the team department or organisation. And it also strengthens and encourages teamwork by practical example.