15 skills that are hard to learn but will pay off forever

The best things in life may be free, but that doesn't mean they won't take time, sweat, and perseverance to acquire.

That's especially the case when it comes to learning important life skills.

To ascertain which talents are worth the investment, one Quora reader posed the question: "What are the hardest and most useful skills to learn?"

We've highlighted our favorite takeaways, as well as a few other skills we thought were important.