On true feelings

I read this post on Papernstitchblog a while ago (yes, it’s a year old – I’m behind the times, OK?).  And it got me thinking about stuff.  About jealousy and feelings one feel guilty about having…especially as a Christian, feeling jealous of someone is just not on.
But…..my question to you today is: when do you know what you’re feeling is what you’re feeling?
Let me set you an example:
A {person I know} announced a while ago on her blog that her items are now available for sale at {a shop}.  
{pictures removed}

Firstly I was very thrilled and glad for her sake, but underneath there was a sharp pang.  

At first I thought I was being slightly jealous and rather mean (oh, the guilt).  
But as I lay in my bed that night trying to find sleep behind my eyelids, I came to the realisation that what I felt was indeed NOT jealousy – that horrid thing that’s even called a monster; no, it was regret.
Regret that I came to so late in my life to realise what I’m capable of.  Regret that I have a deep fear of just going ahead and resigning my job.  Regret that I cannot get into my car and drive around to find shops to carry my stuff.  Regret that I cannot afford to get someone to help me in the house – which would allow me more time for creating.  Regret that I’ve allowed for so long that other people’s idea of ME be enforced on me.
So, when do you know what you think you’re feeling is indeed what you’re feeling?

{Editing note:  I have been asked to remove all references to this person and her business.  Although I don’t understand why, I respect her feelings.}