I actually have a prescription for concerta :p, and yes, it's is ritalin, but in doses that get released at regular intervals, making one pill last an entire day.
A normal dose makes me normal, as I'm usually hyperactive, a double dose makes me really hyper. You taking 3 pills would be really bad, and even worse combined with alcohol. They would all be overlapped too, because they last for a good 16 hours each.

Myself, I've taken ritalin and had a drink afterwards. For some persons that need ritalin, it works fine, but for others, not at all. It worked fine for me, but I didn't take a full dose that time. The reason we're told not to drink alcohol in conjunction with our meds is that the effects combined with alcohol are unpredictable at best, not because they always have really bad effects.

Btw, ritalin is basically a sort of amphetamine :p.