Grandfathers have rather modest roles in the lives of 19-month-old granddaughters. This is especially true when the hassled parents are scurrying around getting ready for an early train.

So it was that the management of juice consumption – pronounced more or less “dzooosss” – fell to me this morning.

There arose a quandary resulting from (a) her desire for dzooosss and (b) her simultaneous desire to run around in a carpeted room.

Even dim-witted grandparents are well aware that (a) + (b) + 19 month old = disaster.

The young lady was adamant about simultaneous running and dzooosssing while the buzz-killing grandfather held out for either running or dzooosssing but not both.

There was an attempt at tears to see if that would work. It didn’t though there was a minor flurry of parental “what’s wrongs?”

Plan B involved “down, down, down” and lap-exiting wriggling.

“Fine” thought the grandfather despite minor tugging at the dzooosss.

There followed about 30 seconds of choice (b) before a return to the lap for choice (a).

“Well done,” said he. “You are now more mature than any member of the Congress of the United States and probably even the President himself. You may have this or that but not both and crying will get you nowhere.”

The parents took heart at this observation and even the expert grandmother noted a modest drop in my dim-wittedness index.

One lesson taught; 436 to go.