Even further back there is the work of RL Moore at the University of Texas at Austin, MAA column.
Showing people how to do something that is totally new to them just does not work. We have to first understand what the issues are. The frustrations we all feel when we are first faced with trying to assess mathematical arguments is unavoidable.
If learning mathematics is like learning to ride a bike, learning to evaluate proofs is like learning to ride a mountain bike really well.
The best thing is to just sit back and enjoy the roller-coaster ride!