What were the prevailing attitudes towards WWI at its outbreak and during the early stages?

Each of the original belligerent countries believed itself unbeatable, and it would only take a few weeks for them to vanquish its enemy. In many ways, each was like an untested MMA fighter who was great in the workout ring but had yet to have a real match. Since they made guys (or gals) tap out pretty easy, they were itching to meet up with a 'worthy' opponent & put the hurt on 'em.