Knowing the motives why someone does something is a useful piece of information. Sure, if I'm dying I'll take everything to have another chance. But if I see so

Knowing the motives why someone does something is a useful piece of information. Sure, if I'm dying I'll take everything to have another chance. But if I see someone wanting to help me for no apparent reason, I surely will ask questions like "why" or "is there a catch"?