When we think about our lives, we generally expect that it's the big events that will bring us the most joy later on--remembering that amazing trip to Tahiti, say, or that huge work success. And certainly sitting on a South Pacific beach isn't going to do your happiness levels any harm, but according to recent research we've posted on previously, people are actually pretty bad at guessing which recollections will bring them the most joy.

Everyday events, it turns out, make us far happier to remember than we expect. So while a simple coffee date with an old friend or a night in cooking for your better half might not seem worth remembering, thinking back on these simple occurrences actually can bring us great pleasure later on.

The question, then, is what to do with this insight. Author Gretchen Rubin has a simple but powerful suggestion, which she shared recently in her Happier podcast. It's a super-easy habit that can help us squeeze extra enjoyment out of the small, everyday details we usually just forget. It's called a single sentence journal, and it's pretty much just what it says on the tin.

A journal you can actually keep

"All you do is write one sentence a day," Rubin says. "If you're like me and like many people, you are sort of periodically swept up in this desire to keep a journal." But those fantasies of devoting lots of time to recording deep thoughts and in-depth recollections usually founder on a simple reality: keeping such a long-form journal is really time consuming.

The solution? Keep the journal idea, but ditch the length and write down just a sentence or two each day to record your most prominent memories. You might think such short entries aren't enough to make any difference in your life, but Rubin insists that this idea is both manageable and impactful. "One sentence is enough. When I look back on it years later, that one sentence really does keep memories vivid--it really does bring back the past--which is one of the things you really want a journal to do," she says.

As science suggests, those memories are bound to make you happier than you expect, but Rubin also notes that "we tend to write down the happier things," which also focuses the mind on the positive aspects of life, boosting joy with very little effort.

You can journal about any aspect of your life--including the process of starting a business--or nothing in particular and still reap rewards. Just make sure you keep your journal somewhere handy to make recording that short recollection of your day super-convenient, avoiding any excuse to skip days.