I had a sneaking suspicion that this might be the case. Classic example = put Finn on floor to play with toys - return a short while later - not playing with toys as mummy directed but rather with aunty leesie's frankie mags that mummy had yet to get round to perusing [don't worry lees - only slightly dribbled on and a couple of misshapen pages]
This morning Finn decided hanging out with toys was unexciting and proceeded to chase mummy and big sisters into the kitchen ableit at rather a leisurely pace.
Oh what fun! I'm going to need to dig out that playpen again