A lot to roll over

So I was dropping Krew and Ryler off at my moms and I laid Krew on the floor just after feeding him and he was playing like crazy.  He attempted to roll over a few times so I hung around until the point where I was almost late for work.  I was sad that I couldn't see him do it but was sure that I would see him do it the next day.  I didn't even get down the street and my mom sent me this picture.....He probably rolled over the second I shut the door to leave her house.  I was really sad to have missed it but I bet it was fun for her to get to witness it for the first time.  He is just barely 5 months so its about time.  I've been told that it takes longer for bigger babies to do things and I think that holds true!