"Best", I dunno...I tend to find the silk purse in even a manure-covered sow's ear, so hey...
But I'd have to say that as a whole, my 40s were my "dark years". Combinations of disappointed idealism, unrealistic expectations, financial/emotional stresses of raising kids, frequently out-of-sync emotional/sexual bonds with my soulmate, just about everything I needed to be "happy" I was seeing far too often through the lens of "you should be doing this for me and you ain't, so why do you hate me so fucking much?" I was a dark SOB, and I was drinking/etc. in a very "professional" manner, which is to say that I had developed the skills to be totally blitzed yet totally functional in a totally unnoticeable manner. Needless to say, that only fed the cynicism...
Then one day, about a year or so ago, it all just lifted. I realized that life is finite, but happiness isn't, not if you take the gifts you get and accept them on their own terms. I'd long had this attitude about things, but had always had a hard time applying it to people. "High standards", and all that. I stopped withholding out of resentment and started giving out of joy, and guess what? Life got better. LTB & I have always been close, but it's often been a "stromy road", i you get my drift. No more - we're like newlyweds again , with the exception that now we know what type of person the other is. The "unknown" is pretty much gone and the passion remains. A highly recommended state of affairs, trust me...
I've "let go" of a lot of things - and not just "bad vibes" - over the last year or so. Some have come back, some haven't yet but no doubt will, and some are most likely gone for good. I no longer feel like a middle-aged guy starting to turn the corner to come down the homestretch. I feel like somebody who's lived a lot and is going to live a lot more. What happened "then" was exciting, new, and challenging, and what's going to happen can be, should be, the same. I've got a beautiful woman who loves me at least as much as I love her, and the kids are finally working their way towards total independence, each in their own way. Money's still a roller-coaster, but w/o those lingering resentments built from disappointments (not least of in self), hey, we just deal with and then go to bed.
I don't play nearly as much as I used to, but when I played more, I was less happy as a person. If the time comes when I can paly more and not get back into that negative personal vibe, hey, good. If not, oh well. Like the song says, they can't take that away from me... I've become convinced that keeping a truly creative mindset and a deeply joyful spirit are not mutually exclusive qualities, but I also gotta say that, in these parts anyway, that appears to be a distinctly minority viewpoint... But shit - with only one life to live, I'm not such a super-heavy, potentially world-changing motherfucker that it's worth fucking up other people's lives, including my own, for the sake of being able to say "Fuck you, I'm an ARTIST." And again in these parts anyway, that appears to be a distinctly minority viewpoint,
So I gotta say, this time right now just might be the finest time in my life. For now anyway.