Where do you get this jealousy from ?
Both siblings had done very well out of their parents, in fact it was because they were both over-indulged that they became as they were, so it wasn't just Jeremy.
Didn't Nevill tell Barbara Wilson that " you do your best for them ( meaning both ) and this is what you get ".
The one thing that was missing from that family was love and a close bond between parents and siblings.
Jealousy isn't necessarily a rational emotion.
We could all say JB was relatively well off for his age, but that doesn't mean he would be fully appreciative of that, especially in his early 20's. It doesn't take long for anybody mixing in circles where even more money or privilege exists for you to feel hard done by.
For a seemingly suave and flamboyant young man, a flat in London would be quite something. A modest home in Goldhanger less so.
'The grass is always greener' may well have been something JB believed regardless of his actual circumstances.
As for love and bonding with parents, that is so subjective and it's very easy to look back and find evidence to suggest June was difficult. There is also plenty to suggest she was a typical doting mother too.
I could just as easily look at aspects of my own parents that could be seen as highly judgmental, oppressive, old fashioned etc. But I could also demonstrate love and care in abundance too. I think many of us could say the same.
I know plenty of churchgoers who are committed Christians. They are normal people to me (just hold some irrational beliefs). To others they would be bigoted religious crackpots.