What are some examples that might help me recognize bipolar disorder?

Mood swings. Bipolar disorder as the name implies involves highs and lows in mood. Period(s) of depression with at least one episode of mania ie euphoria, insomnia, racing thoughts sexual/financial indiscretions etc.
The hallmark of. Bipolar is mood swings. So someone who is depressed one week and euphoric the next may have bipolar.