Go find yourself a 5 year old and a 25 year old. Begin asking them questions about what, in life, matters to them. There is an important lesson you'll learn from the child, because if there is one thing that children know better than adults, it is that having fun is important.
You have to enjoy the things that you do, and sometimes, have a little fun with them. No matter how dreadful what you're doing may seem, you must embrace it and find the enjoyment within. Take what you do for a living. There is some reason you chose to do whatever it is you do. Even if it is not the most glamorous job in the world, there must be something enjoyable about it. Whether it is the job itself, the people you work with, or the atmosphere you find yourself in, something must make it enjoyable.
Now we move on to the fitness aspect of this concept. If you are doing something you don't enjoy, you aren't going to do it as often. So if you do not find lifting weights enjoyable, you aren't going to do it as often. You will become more apt to skip days at the gym. My question to you is, why lift weights then? There are so many other ways to remain fit, probably many more that you would have fun doing. Go out and figure out what those things are. Many people have fun during group exercise classes, they attend them more often, and they find themselves in better shape than prior. Any type of physical activity promotes fitness, so go play a sport. Go walk through the woods or around a lake and take pictures. Get up and do something that you have fun doing.
Fun is also important to your mental/emotional well being. You cannot always be the stick in the mud. Someone who is serious all the time will have higher levels of stress, predisposing them to an abundance of medical conditions (high blood pressure, heart disease, ulcers, etc.). So even if it isn't a fitness activity, find yourself something FUN to do.
