It is my understanding that the feeling from taking all of the stuff you took is going to feel different from what it's felt like using any one of the drugs feels like independently, or what any combination of some of the drugs you took have felt like before (ie addy plus weed, or klonopin plus weed and adderall). Since you've never taken it all together nor have you experienced adderall and hydro at the same time, you don't know how it all interacts together and what each drug did to change the combined effect. For example, if you've experienced adderall and weed together, and you had taken adderall and weed and hydro, it still doesn't tell you what adderall and hydro are like together. You may already know what adderall and weed is like together, and maybe you also know what each feels like independently, and maybe you also know what weed and hydro feel like. But until you take all 3 together, you don't know what adderall+pot+hydro feels like, and you still won't know what just adderall and hydro are like together. Similarly, combining everything you took doesn't mean know what it feels like for you to have adderall and hydro together. What you know for certain is that combining 40mg hydro, 90mg adderall, 1mg Klonopin, and however much weed you smoked feels like when you combine them and time it all the same way you combined it all last time. That's why scientific testing only allows for one variable to be changed at a time. If you change multiple variables at once, you won't know what changed what.
Another way to view how taking all of it at once is different is to take into account that some drugs work by altering brain chemistry in the same way, and it's possible to create more of some chemicals than your brain can absorb, such as serotonin and dopamine. For instance, all the drugs in the same class as Prozac (SSRIs) work by altering brain chemistry. For those who find these drugs successful in alleviating their depression, their depression is caused by them getting too little serotonin. It's not because they aren't producing enough serotonin, but because their brains can't absorb enough. These medications are understood to work by creating more serotonin receptors in one's brain, allowing more of the serotonin that is already being produced to be used. Since serotonin is the, for lack of a better term, happy-happy brain chemical, it makes these folks happier when they have more of it in their systems than they would otherwise have. Another example to take into account is how adderall creates a high. It is to my knowledge that is fun because it increases another good-feeling brain chemical: dopamine. In fact, weed also increases dopamine, as well as serotonin, besides other effects it also has on brain chemistry that results in it's high. Like serotonin, there's only so much your brain can absorb; you only have so many dopamine receptors in your brain. So, at a certain point, increasing your dopamine stops having an effect. After a certain point, using more of any drug that increases one's natural levels of these chemicals will stop getting them happier, or rather, higher in these ways.
Therefore, it's easily imaginable that some people can take in more dopamine than they can actually use when they combine multiple sources of it, like by using marijuana after taking adderall. In fact, in SWIM's opinion he can max out on the effects of extra serotonin and/or dopamine by smoking pot alone. So while somebody may have experienced these highs separately, together could likely feel different than simultaneously experiencing an addy high and being stoned. Combined, they have a good chance of feeling like something else entirely. Now, I don't know the precise mechanisms of action of each drug you ingested that night. However, serotonin and dopamine are not the only chemical that you can ingest more of than your body can use, in essence wasting any extra you've taken past that, since it won't have any additional effect. Therefore, when you take it all together, the effect is different than the feeling of any of the components individually, or any experience you have had before of combining some of the components. In addition, some chemicals and things that are fun when you have a certain amount are sooooo not fun when you have wayyy to much, the way alcohol can be. It's just so incredibly unlikely that taking the all of what you took together felt the same for you as taking just addy and hydro together would feel like, and that the negative effects wouldn't necessarily be the same.
