If he had been, insomnia might have been more of a problem as he tried to work out how to pay for a growing proportion of that 70 million – Britain’s senior citizens.

Whether at Westminster or at Holyrood, the question of how to pay for the increasing number of old people is unavoidable.

The Labour Government has already moved in that direction with plans to raise the retirement age to 66 in 2026 and the ante has been raised by Shadow Chancellor George Osborne who, earlier this month, said that the Conservatives would raise it by 2016.

In Scotland, the big problem is the cost of free personal care. It was former First Minister Henry McLeish’s flagship policy and he introduced it in the face of opposition from some of his own ministers, including Health Secretary Susan Deacon.

It now costs more than £300m a year. The SNP Government is committed to it but no matter which party was in power it would be a very brave decision to scrap a popular policy which has now been running for seven years.

Free personal care may not be exactly as described but it is looked on enviously by people in other parts of the UK and it would be political suicide to drop it.

To keep costs down, governments have to improve older people’s health and to do that they have to improve young people’s health.

Many older people have diseases and infirmities which are the consequences of lifestyles led 40 years earlier.

John Curtice, professor of politics at Strathclyde University, warns that although the issues of old age may become more prominent,

that doesn’t necessarily

mean the state, no matter who is in power, will end up spending more money.

Faced with rising social care funding, the politicians will find reasons to withdraw parts of the package to keep costs down.

Spending money on persuading people to live healthier lives now should save care costs in later years.

Political parties must also concern themselves with the voting patterns of an older electorate.

Old people turn out to vote but after the age of 75 turnout begins to fall off, either because of illness or because people are housebound.

However, with better health more of them are likely to continue voting for many more years and who their votes go to could change.

Professor Curtice points to “differential” death rates. Working-class people are more likely to die early and they were more likely to vote Labour so as a generation ages it tends to become more Conservative.

What’s crucial is not so much the average length of a life but the class differences and those have been changing in recent years.

In Scotland, there’s also another dimension – the SNP.

If its current popularity continues, it will be expecting to attract more supporters and to then keep them within the fold.

If the population projections are correct it could be a substantially bigger party than it is now and certainly by 2033, when the number of people aged over 75 will have increased by 84%, Scotland will be a very different country to what it is today.

There has probably never been a better time to mobilise the grey vote.