It's also a symptom of drastic inconsistency in downward pressure. This force is the downward pressure that you want to maintain while drilling. This action is hand-drilling in slow motion. It may give you a better idea of what needs to be happening. Strength's a factor in hand-drilling, but not as much as most people think.
Success is mostly in technique.
Some people don't get fires or coals in our full day classes even with a lot of coaching. Just keep practicing and try tandem drilling with a friend. Two or more people taking turns can often get a fire where one cannot. If you're one of the naturals and succeed easily, don't think you've got it made, especially if you want to be able to rely on this skill for your survival someday. Practice, diversify in materials, and observe others' techniques.