True Lookout, also think Jeremy was more interested in girls than his studies if we (like Adam) believe everything written about him. 
Not being unkind,but Jeremy thought about Jeremy as every young man would be the same at that age,and I agree Maggie, it was all about girls,clubs,restaurants and generally a good time as though nobody else mattered.
How many young brothers know all about what their sister's up to,or who even bothers to find out about her health.? He only repeated what others would have done when he'd said she was a " nutter ".He said it without any understanding of her condition,as his parents wouldn't have sat him down to explain about it. Yet he's been condemned for everything he's said and done.
Jeeze,he was no Crippen.!