For me it has a few factors: I learn, memorize, and internalize through argument and learning to explain things to others. Eventually my skill ceiling rises i

For me it has a few factors: I learn, memorize, and internalize through argument and learning to explain things to others. Eventually my skill ceiling rises in a topic where this no longer applies much. But, if I can spend 5 seconds to save someone 5 hours, I'm likely to help unless I thoroughly dislike the person - it's just too high of a positive impact. With my peers, I'll accept much worse ratios (e.g. spend 1 hour to save you 2) under the vague unstated assumption that you'd do the same for me, or it'll help accomplish our common goal faster. And in the special case of helping people with research and problem solving skills, it'll sometimes make people less annoying :)