Everyone needs to be themselves and enjoy life; otherwise, it's just not worth living. People should also respect each other's lifestyles/opinions/privacy/property/etc. At the very least, they should show an initial respect for everyone regardless of things like gender and race. If others do something to make one dislike them, fine, dislike them, then. It's stupid to judge someone without knowing anything about them. One can't just live each day carelessly; people also need to be responsible enough to continue to live, e.g. earn enough money to cover necessities. Being happy is important, but it's equally important not to destroy the happiness of others.
Without happiness, there's just despair and suffering. Such feelings are obviously not the sorts that people would want to experience, so what meaning is there in living only to face them? First, a person needs to be themselves to be happy. Anyone can put on a facade to create friendships, laugh, and do things that people typically associate with "having fun", but they won't truly be happy if that isn't what they truly desire or enjoy. For example, a person who enjoys video games might not have fun playing basketball even though the rest of his peers do. That's not to say they should just stick to the things they know they enjoy and never try anything new; one won't know whether or not they'll enjoy something until they try, or at least until they try something similar. People just shouldn't put on an act or force themselves to do things to please others; they should be concerned about their own happiness, not concerned with making empty friendships. A person can change their personality to match the interests of the different people they wish to appeal to, but it's futile. They could have dozens of "friends", but they would be much happier having even just one or two true friends - people who they could just be natural around, and people who would be natural around them.
People shouldn't judge their lives as undesirable experiences based on only bad things, though. Some people believe they won't have a meaningful life until they have their dream job, a house, a family, or some other shallow goal. Even "small things" like playing video games, talking with friends, eating delicious food, watching TV, taking a nice, hot shower, or just appreciating the beauty of nature qualify as enjoying life. If it's even just one little thing in life that one appreciates, that makes it worth living. If one currently doesn't even have anything of the sort to enjoy, that's not to say they never will. Some people see the universe as absolutely enormous, and they compare our little planet Earth to it and note the insignificance of our existence or assume that our lives are extremely limited. That is not true; there's a whole lot of stuff to do and see in life. So what if Earth is just a spec in the grand scheme of things? A human being is a microscopic spec in comparison to that spec; they'll be kept more than busy on that spec, and it's just selfish to think they could possibly need more.
Some people will laugh at those who live for "small things" like what was previously mentioned. These are the people that have not put much thought into life, so one should pay them no mind. These are the kinds of people that just follow society's guidelines to being popular and/or successful - they aren't even living their own lives, they're allowing others to control it for them. People should make their own decisions, and others should respect such choices. However, these decisions must also respect the will and well-being of other people. People obviously won't be too happy about other people forcing them to do things or other people benefiting themselves by taking away from others. For example, person A wouldn't be able to enjoy life as much if person B decided that cutting off other peoples' fingers was enjoyable and they ended up turning person A into their latest victim.
Even if a person's instincts tell them that disrespecting others for their own benefit would make them happy, they must have restraint. We are human beings, not animals. We are capable of thinking and making decisions that aren't based on instincts. With all of the possibilities in life, they would surely be able to find something they could enjoy without disrupting the lives of others. If not, then they could attempt to be rehabilitated so that they may live a normal, enjoyable life without putting the lives of others at expense. They can go live in the wild if they can't behave as civilized human beings; humans need to use their brains and have more responsibility. Society is set up in a way that everyone has to contribute to live a comfortable lifestyle with the benefits of every group. Instead of, say, having to produce one's own food, obtain one's own materials and create one's own clothing, and take care of one's own injuries/illnesses, people just need to do one job. We exchange the value of our skills/contributions with money. For the sake of themselves and others, people need to comply with this to continue living.
If one enjoys or might later enjoy anything in life, no matter how small it is, life is worth living. To allow oneself and others to enjoy their lives, people must respect each other. To continue living, people need to be responsible.
February 03, 2009