Milk happens?

This morning after Eli had his breakfast, he was sitting at the kitchen table playing with his cars when I told him I had to run upstairs and change my shirt so we could go to the store.  He said he was fine with this.  The foolish move I made was to leave him with a "big boy" cup of milk.  I was not upstairs for 1 minute when I heard Eli call to me.  Something about his milk falling down.  Of course I knew what this meant so I hurried down the stairs.  What I found was not exactly what I expected.  

Eli was lying on the ground on his stomach, not crying or upset, just lying there.  His milk was in giant splashy puddles all over the floor.  I asked him what happened.  He said his milk fell down.  I asked if he fell down too.  Yes, with no other explanation.  I have no idea what happened.  But as I was cleaning up the milk, Eli said to me repeatedly, "Sometimes things just happen.  Sometimes it happens."  I told him that was true.  Sometimes cups of milk just fly off the table.  It turns out that he is using the "sometimes it happens" response for everything today.  Why are the cats fighting?  Why don't my pants fit?  Because Mommy, sometimes it happens.  

Here's a picture of the unaffected toddler.