Actually it's common to go for long periods of time between episodes; you sound rather typical to me. My previous pdoc told me that she had 'plenty' of patients who had gone 10 years without episodes (and she specialized in BP).

So don't worry. Your episodes sound classic actually. And I certainly do not think you're faking it because you have relatively long periods of stability. Remember that this is a BP forum and therefore there may be more people more consistently ill than the general BP population (though I can't be sure of this), but it's better not to compare yourself. I'm happy for you that you've experienced periods of stability.