Hard work is always necessary but its not something that is neutral and the same for everyone. If you're talented then the work is going to feel easier. Your energies are flowing, you are being yourself and putting your strengths to use.

If you're not talented its gonna feel lika an uphill battle. You get out of tune with yourself. Energies are dammed up. At some point you get mental problems. You can still improve yourself to some degree but at some point you'll hit the wall. People cannot do violence to their own nature forever.