Oh, boy. Now you suddenly have me on the spot. It's actually a long, frequently-updated podcast in German, and I'm afraid I'm not going do it justice, because I don't speak German perfectly and sometimes zone out. I distinctly remember, though, that he quoted some study that correlated like 80% of happiness with... just, kind of, being happy in the moment, with the rest combined coming... Oh, wait. So... Oh, damn. Okay, so I don't remember the numbers, but, like, happiness from achievements lasts generally only a week or something...

Wait, wait, I'm hopefully going to listen to another episode today and get back to you!

Or if you speak German, the podcast is called "Achtsamkeit leben - Dein Podcast mit Peter Beer".