Spending lots of time with one person year in and year out, is no mean feat. In fact, it is an almost superhuman feat. But often, people will feel quite mean after a while. Most people, put together with just about anyone on this planet will get irritable after a while. So yes, your fantasies of upping and leaving are normal.
Ho-hum. All spouses get bored with each other at times. This is simply inevitable, given the amount of time you spend in each other's company. After a while, little things start to grate, such as the way he slurps his coffee and the way she laughs when she's on the telephone with her mother. But rest assured, if you were to spend that amount of time with anyone on earth – and that includes movie stars – something they do will drive you crazy within a very short while. Think about it – there are things you do that also drive your spouse nuts.