Despite thousands of years of evolution, the human body is still meant for long-distance running. The development of habitual bipedalism differentiated humans from other mammalian species. Prior to this, human ancestors traveled on four legs, only being bipedal for short amounts of time to run.
The purpose of humans having two legs is to make running easier; because of this, humans are the best long-distance runners on the planet. In a short race, our race does not have a chance, but in the long run (literally), humans have the upper hand. The human body is designed for long-distance running, and your body will reward you for using this function. Despite initial pains when you start a run, you will feel better when it is finished.
The biggest mistake people make is to stop a run before the body has decided to reward you for the run. General discomfort is the side effect of a run before the reward center is activated and endorphins are released. Once you get past the initial discomfort of a run, it gets better. The endorphin-release timing is different in everyone, but the average person can reach endorphin release by two to three miles into their run.
What turns people off from running is that initial discomfort. If you can push through that, the run becomes enjoyable. Humans are designed to enjoy running, so try to do that. Running should not be a chore and can be an enjoyable hobby.
After a run, you may experience an improvement in mood and an energy boost. Other beneficial side effects of running include mood improvement, renewed energy, increased metabolism, being able to eat a ton of food while not gaining weight, fat loss and increased fitness. The list goes on and on!
Negative side effects of running include spending a ridiculous amount of money on unnecessary running gear (ex. energy gel and a fuel belt for long runs), hating your life for the first one to two miles of your run and getting up ridiculously early to avoid the heat in the summer.
Personally, I believe the positives of running outweigh the negatives. The mood boost and being able to eat half of a large pizza with no consequences outweigh the fact that I spent $200 on a running watch and $80 to spend a Sunday morning running 13.1 miles (half-marathon race fees are ridiculous.)
In conclusion, start running!
Get a pair of shoes and some comfortable shorts, then go for a run! Ride out the first two miles, and then just enjoy the benefits of running.