We've all had a boss that we've not got on with during our careers, and some of us have had those that are just plain bad at their job. Even though you get a lot of inspiration from the people you work with that are effective in their role, you can still learn something from the ones that aren't.
They teach you exactly what not to do
This may sound obvious, but the best thing you can learn from bad bosses is exactly how not to go about your job. However, it's not enough to think to yourself that you just don't want to be like them. Instead you need to address the specific things they do that you dislike and how you want to be different.
It may be how they talk to people below them, the way they run a team or how they try to motivate, but realizing what it is that you don't like can make you a better manager. As well as doing this, it's important to think about the impact this has on you and your colleagues. This will make it easier to change your actions and ensure that you don't make the same mistakes they do.
You'll never take a good one for granted
Bad managers also teach you a very unique and valuable lesson; to never take good leaders for granted. This will allow you to be more receptive to the effective bosses you have throughout your career, putting you in a much better position to learn from them. Instead of just taking this for granted and presuming it's the standard a manager should achieve, you'll be able to see how they are able to be so effective.
Whether it's that they are good at motivating teams, really care about progression opportunities, or can consistently deliver on targets, not taking them for granted allows you to learn as much as possible from your good leaders. As well as this, when you have good managers you'll be much more aware of the difference they can make to a team, compared to your worst boss.
Questioning authority is fine, and even important
If you've ever had a bad boss, or even a good one that makes a few bad decisions, you'll know that there are times when authority should be questioned. This is something that the most successful leaders use to their advantage, and an important thing for you to remember during your time in management.
Of course, you need to be able to choose the right time and place to question authority to avoid teams descending into chaos, but teams should always be encouraged to speak their mind. Even when you're someone's boss, you're not infallible and you should never be too big to take advice from those around you.