It's all about perspective

There was a study at Purdue University that showed that golfers that overestimated the size of the hole when golfing sunk more putts.

Further, when using an optical illusion in the lab, golfers sunk shots better there too.

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Perception matters.  And positive perception matters if you are trying to have a good day.

What we see and how we choose to perceive things can make a huge difference in how we do and how we feel.  
If you go into a situation at work (or school, or home) and expect that whatever happens is not a bad thing; not an attack against your happiness or your peace you'll see and hear it differently.  You will react to it differently.

In the same way, if you assume that Mondays will be Mondays or that every day not the weekend is less than the weekend it is likely that you will make it so.

None of this is a surprise.  But making a choice to see things differently may have surprising effects.

What's the worst thing that can happen if you change your views?  You'll make today a good day.