We have a cognitive bias towards our own ideas, because we make them.
Partnering with people, or working in teams, is a step towards insuring against that bias.
That’s not to say your ideas aren’t good, you might just have a harder time picking the good ones from the bad ones than someone who doesn’t share your bias.
An even more compelling argument for teamwork is that finding good ideas requires a mass of bad ideas to be had and filtered through.
“The goal isn’t to get good ideas; the goal is to get bad ideas. Because once you get enough bad ideas, then some good ones have to show up.”Seth Godin
If you’re working with a partner, the amount of ideas you generate doubles. This means you find the good ideas faster, and can work together to capitalise on them.