Being someone who enjoys reading a fair few blogs every day, 'living in the moment' was a quote which stood out to me a while ago. I unfortunately can't source the blog since I don't remember it, but in essence, the post claimed that living the moment tended to make people happier.
Thinking about it, it's actually quite logical. If your mind is in one place and focused on what you are doing rather than what you could be doing, you won't feel as though you are losing out on anything or are hard done. This way, your mind is fixed on what you are doing, which is the 'best' thing possible at this moment in time, rather than something you would rather be doing elsewhere.
If we look at it like the above bar chart, the difference between the two is what would tend to make one feel pretty bad because you know there is something better out there which could make you happier.
Trying to stay in the moment isn't always easy, but it seems to be a nice idea and definitely one worth trying out.
18 year old back-end software developer. Curious. Always learning. http://Riotcleanup.co.uk && http://PDFtribute.net. English and French.