If it's not already been pointed out, the fantasy that the OP believes in of humans wandering around in a sort of garden of eden picking fruit so they don't have to kill any of those poor little animals would be associated with a time when our hominid ancestors would have had brains the size of chimps, who BTW are observed to hunt, kill and eat monkeys on occasion. It is believed that our brains grew when we started eating more meat. By the time we were something you could call human, we had LONG been out of that environment where sustaining ourselves on a mostly fruit diet would have even been possible. So the picture the OP paints of homo sapiens living off of fruit is pure fantasy.
I've had 2 friends that attempted to "live off the land" and I think if anyone tries to do this, even for a little while, it could be instructive. Both were vegetarians when they started their quests. The first went to tracking school before setting out and when freezing his butt off one day the instructor said to note who was cold and who seemed to be doing OK. He quickly worked out that it was the vegetarians in the group that were freezing. He ended up living in the New Jersey wilderness (sounds weird to say that, but it's there!) for a little over a year. He learned to make small traps and lived off of squirrels, rabbits and whatever edible plant material he could find. The other friend refused to give up the vegan belief system and lasted 2 weeks before he had to give up because he was starving.
There's a reason no one has ever found a native culture that has survived on a vegan diet. You simply can't live off the land that way and survive. Our species has evolved eating meat for so long that our digestive system isn't equipped to be able to derive enough sustenance from whatever plant matter you can gather up. There are some fairly modern cultures that are vegetarian, but eat milk, eggs, etc. but the whole "vegan" thing is really a completely modern thing. The amount of supplementation with things like plant derived protein powders, B12 supplementation, a dizzying amount of food combining to get complete proteins, flying fruit in year round from all parts of the globe, etc. etc. make this sort of diet only even remotely survivable in our modern world.
But I'd invite the OP to not take the second hand stories of some guy on the internet with anything other than a grain of salt. Rather if you have the time, inclination and most importantly actually BELIEVE in your Vegan ideals enough then go try living off the land without eating any animals. Try it for a few weeks, blog about it, take some pictures before and after, whatever. If you can actually do it I'll tip my hat to you and say "well, looks like I was wrong".
Apathy is tyranny's greatest ally.