The thorny question of what pupils should learn in school
Is there such a thing as a "curriculum for life" ?
That's what the Lib Dems want to offer for children in England.
If you have a child at school you'll know how much what they learn is already changing.
The end of primary school tests known as Sats have been made tougher, with more complex grammar and maths among the changes.
And if your household is going through the agony of GCSE revision, you'll know this is the first year of the new English and maths exams which are also designed to be more challenging.
There has been so much change that schools have been complaining they can barely keep up.
The unglamorous, but important issue of what children learn at school rarely features in election campaigns.
Yet subjects matter because it influences the choices your child can make about their future job, or what they want to study at college and university.
So it's striking that the Lib Dems have chosen to make the subjects taught in schools, the curriculum, a large part of their education election offer.
Their manifesto says this would mean a shorter list of core subjects all state funded schools would have to teach.
But they also want learning about money, and mental health to be included alongside age appropriate sex and relationship lessons.
It is only weeks since a change in the law to make sex and relationship education compulsory for all secondary schools in England, with primary schools teaching just about relationships.
There is a promise too to protect creative subjects like music, art and drama amid concerns that tightening budgets and a focus on results are squeezing them out.
Quite how they would be protected isn't clear, although the party is likely to argue that promising extra money will help.
So should politicians be deciding what your kids learn at school?
An interesting question as some recent Education Secretaries have had very definite views.
The Lib Dems are making a bid to take the politics of changing governments out of these decisions.
They want to set up what looks like a new quango - an Educational Standards Authority - which would bring in changes after consulting teachers.
But in the end, when there are issues in schools, just like in hospitals, the buck stops with politicians.
Voters tend to have little time for a senior politician trying to outsource the blame for any decisions.
So, as the Lib Dem manifesto delicately puts it - there would have to be some way of retaining "legitimate democratic accountability".