It’s actually very easy to be happy and stay happy if one is determined to be.
To stay happy, never take stress thinking about what others think about you. You will meet all kinds of people— jealous, cunning, people who will try to take advantage of you and what not, but not bothering about them and keeping a distance from them is a key to satisfaction in life.

Never make important decisions in hurry. Think of every loophole, all the pros and cons. Like in programming, you don’t wanna miss out the possibility of any fucking test case, otherwise all the hard work will go in vain and you end up wasting your precious time.

Have self control! It matters a lot. Aim for the future life you have dreamt of rather than wasting time on petty things which will give to temporary doze of joy. Keep calm and carry on!

Never get stressed or depressed due to failures. Take some time off and blow off some steam. Don’t overthink about the failure unless you are mentally prepared to face it. Try to ponder about your mistakes and make bold steps to rectify them.

Never forget who you are! Stick to your roots. No matter how rich or modern you have become, never forget your past and your background. Cherish the good memories. Never forget being humble to people.

Not being an asshole to people who care about you. Respect them and cherish them. Trust me, without them life comes crashing down. They are like Dynamic Programming to your lame and naive iterative code. In short, they make life simple.

Have a constant urge to learn more everyday. Set small small targets and achieve them within a reasonable period.

Have a healthy schedule. Workout. Eat healthy. Meditate. Don’t binge watch Netflix for 20 hours a day.