I listened to an investor share his investment thesis and why he chose it. For a surprising reason, he invests in clean tech. He grew up near contaminated soil that affected him and others in his hometown. Because of this exposure, he’s been getting treatment (including multiple surgeries) for a failing organ for years. The organ is vital—if it fails, he could die. Because of his personal experience and that of others in his hometown, he’s been passionate about clean tech investing for several years.

This investor isn’t focused just on returns. He wants to make sure others don’t have to endure the suffering he has. That passion is what drives him, and he puts that same passion into helping the founders he invests in.

If you’re a founder seeking capital, consider asking potential investors why they chose their investment thesis. If their story is as compelling as this investor’s, you’ve likely found a good partner.