The point is, I was geeky and curious enough to study how our brains process emotions and what to do to make it easier to be happy. The thing is: instead of comparing yourself (your good/bad fortune, your skills, your wealth) to others, you should compare yourself to your past self -- and then give yourself small goals every day, and achieve them - and then constantly make comparisons ("Earlier this day, this house was dirty, but now it is clean!", "Earlier this day, I sucked at this song, but now I know the lyrics by heart!" "Earlier this day,...")
"A person can get used to everything" -- this is both good and bad. Just as we can get used to bad stuff, we can get used to good stuff and we don't notice it anymore. A person who won the lottery won't feel happy for long, unless he will constantly aquire new things with that money -- and then there is the problem that people suck at determining what they like, so he may end up spending a lot of cash on worthless crap, and also material wealth can feel empty in the long run... and there's the matter of winning the lottery in the first place -- too improbable to count on it.
Our minds evolved in order to help with our survival in the wilderness (when we were still cavemen) and because of that, aquiring new skills, and achieving things that require effort makes us happy the most. If you give yourself every day meaningful (but ACHIEVABLE) tasks, and finish them consistently, satistfaction will kick in.
The key is to not to go overboard on the first day and give yourself too much to do. (Many people who want to lose weight for example do the stupid thing and go for half-hour jogs after years of lack of exercise -- oh, btw, I really recommend exercise. When you do it every day you will feel a lot better -- recommened regardless if you want to have a sports-related career or not)
Think what you want to achieve -- be a better writer? Write one page of text a day, everyday. If you manage to keep it up for a week or two without a fail, go for more pages -- and only increase the difficulty when you consider the previous stage too easy/not challenging enough.
Bit by bit. Writing? Start writing page a day. One story/poem a day. Exercise? Twenty sit-ups a day, at a set hour. Too easy? Start with more -- the thing is that you must consistently give yourself small challenges, and win them. When you consistently make yourself promises ("I will do X today!") -- and then KEEP those promises ("Yes! I said I would do X and I did!") it really helps. Constantly compare yourself to yourself from a near past.
Don't be like "I promise myself I will do 1000 squats today!" and then be "Aww, I did only 121 squats before my knees gave up" at the end of the day. Give yourself small promises often, and then keep keeping those promises.
I do this every day and it really helps.
I REALLY recommend reading those. They helped me a lot:
...or, what the hell, have this too: 4#
Remember: whenever you have a large task in front of you, cut it. Still to big? Cut it. Still? Cut. Cut the big task until you can start doing one of its pieces RIGHT NOW.
Like reading... if you have to read something (like above advice) but aren't in a mood, then just say to yourself "I will just read this paragraph and I'm done", and then check if you want to continue reading AFTER you read it.