Matthew N:
So are you saying you think I'm already passing the first few jhanas and not even realizing it? I've had feelings of physical relaxation before during concentration but nothing as profound for me to believe I've attained anything until this point.
There are generally two kinds of meditation we talk about here - concentration and insight. concentration is what gets you into jhanas, and gives you pleasant bodily feelings and relaxes you, etc. it feels good, and is a good way to relax, but that's about it. insight puts you on the path to Enlightenment, or closer for you - Stream Entry, which is the 1st major perceptual shift that happens, the 1st stage of Enlightenment. I'm suggesting you were inadvertently doing insight meditation (observing the impermanence, unpleasantness, and selflessness of all sensations, whether you were doing it explicitly or not), so now you're on your way to Enlightenment and you passed a major landmark, the A&P. unfortunately, what follows the A&P is a stage called the Dark Night that can be pretty unpleasant, so it'd be good to read MCTB and learn all about it, since if my assessment is correct (which i'm not sure about) you'll start getting unpleasant side-effects soon. luckily they, too, are temporary and pass with more meditating, but if youre not aware of it you might feel you're regressing, doing it all wrong, and beating yourself up for no reason, when in fact you're progressing.
Matthew N:
If this is supposed to happen I'm not sure what I'm supposed to do next though, as I lose my focus on the sense of the bliss in the explosions, and the heaviness that brought me there has been abandoned, and focusing on it again just brings back the flashes and explosions your saying are A&P, which I can't hold onto for more than a few seconds before they pass. What should my mind be doing then? As of right now I'm just cycling back and forth it seems through this.
hmm so there are two possibilities...
1) the insight thing i mentioned. in this case you're moving past the A&P, and moving back into it by trying to re-focus on it. what you would do to continue on the path of insight (and lead to the 1st stage of Enlightenment) is to notice everything you are feeling, and to pay attention to those 3 characteristics (impermanence, unsatisfactoriness, and selflessness) which are inherent in all sensations. then you'd start going thru the later stages. a formal meditation that makes this easy to do is called 'noting', you can read about it
here. i recommend reading the MCTB link (the whole book, really) if you plan on doing this as it really lays it all out and you know just what to expect, helps to understand what you're doing and why, what Enlightenment is, etc.
2) you might just be getting jhanas like you were thinking. in this case, the flashes and stuff are signs of the 2nd jhana, and are signs of piti (bliss). those go away on the 3rd jhana, so don't try to cling to them - instead notice that though they are pleasant, they're kind of intense and disturbing (like disturbs your calm), and the sukha (pleasantness) that is underneath is and more all-pervasive and calming is really nice too; that sukha becomes apparent in the 3rd jhana. but i really thing if it is explosions and flashing (and not just bodily bliss) that it's the A&P and it's insight.
Matthew N:
Is there nothing I can do to keep these A&P things going? I know I should not be striving towards physical sensations, but these put a smile on my face for like an hour after I first felt them, I kind of wanted to hold onto and explore that a bit, darn.
hmm with enough concentration it is possible to remain in the A&P thing, but i don't know how feasible it is at this point.. generally once you understand a stage (like you have with A&P if you passed it), you don't linger there anymore, and you just go on to the new stuff (which is less pleasant than A&P, unfortunately). it is a common thing (mentioned in MCTB ) that someone who just got out of A&P wants to go back in and feel the awesomeness there (one of the first times it happened to me i just got really blazed afterward to attempt to up my concentration, heh), but trying to cling to it will not work, unfortunately. if you want to try, you just try willing your mind / resolving to stay in it, but i recommend progressing onward.
oh ya once you get to Stream Entry you get to Review the A&P, so you'll be spending more time in it then, and with good concentration you can remain in it and check it out a lot more (which is recommended).
though the dark night stage is unpleasant, there is an Equanimity stage after it which is really quite nice, much calmer than A&P and quite relieving and neat - so there is good stuff ahead! just gotta get thru the unpleasant stuff (and understand it), first. then after Equanimity is 1st stage of enlightenment, stream entry, and that's always fun.. your concentration will increase dramatically and you'll likely be able to get 1st 4 jhanas easily, without much practice on them. indeed, i might even say it's a shorter route to mastering the jhanas to get Stream Entry first, since once you're there it is a lot easier.
Matthew N:
I know I should not be striving towards physical sensations...
ah don't feel bad that you are feeling good! we won't judge you. and indeed if you are doing concentration you want to initially focus in on the bliss & pleasure and suffuse your body with it until you're filled with it, and once you're satisfied with that you move on. but if it is insight you're doing then it probly won't work.