I think, one needs to ask first what an HG really is.
For me, it always used to be the bag that was the most difficult to obtain (in my case that was the most expensive one on my wish list) and because of that, I desired it more and more and overly glorified it.
I was finally able to buy it (an SC bag) and - don't get me wrong - I love the bag, it's awesome. But it's the same kind of love I already had for other bags before her. I like taking her out, I feel good when I carry her, but an ecstatic holy grail OMG WOW experience? No.
If you'd ask me today, what my HG is, I'd say it's my monogram key holder. I use it every single day for my keys (duh) and my bus pass. Whenever I slide it into my pocket, I'm thinking how amazing the canvas still feels in my hand. When I pull it out of my pocket at the bus stop I smile broadly, because it's just the most perfect, handy little thing.
The leather on the inside still smells divine after a year, so sometimes I sniff it. Did it ever come to my mind to sniff the leather on my holy grail SC bag? Nope, never.
I think the true holy grails only crystalize after one has had them for a while and suddenly realizes how they've added tons of unexpected joy every day.
With the SC I got my HG-bag in theory, but in practice it's not an HG at all, while that tiny key holder turned out to have stolen my heart. I'll just keep collecting bags and surely another one will really stand out again one day. That's what happened after my HG, hope it helped!