Certainly agree with your proposition that anyone who votes in future should understand what they are voting for. I certainly did - after many years, experience and much thought.
I am wondering if the voting age should in fact be raised to, say 23. Before you shout me down: by the age of 21 in the past you were likely to be married and understanding the economics of life - if you were female you were probably a mum. (When pregnant aged 26 in 1975 I was an aged primagravida and a very late mum.)
When the voting age was reduced to 18, most people had left school at 16 and were in apprenticeships or jobs - only a small percentage went on to further education. So voters had some experience of life.
Now we regard 18-yr-olds as borderline children.and how many of them work or have any real stake in their country? And we let them vote!
By 23 most, nowadays should have finished further education and been faced with the reality of the world and how to survive. So that is when, imo, they should be allowed to vote. They will then value it.
OK I'll sit back and fold my arms and wait for the flak (actually, I'm about to go to bed). I think I'm right - youngsters are far more immature than we were at the same ages - and I'm back working with kids so doing comparisons. :)