This CNN article quotes several researchers though doesn't actually provide much details of studies: http://www.cnn.com/HEALTH/indepth.food/sweets/chocolate.cravings/index.html
"We are talking about something much, much, much, much milder than a high," said Piomelli, a researcher at the Neurosciences Institute of San Diego. He reported the work with colleagues in the journal Nature.
But a researcher who studies the brain chemistry of marijuana said chocolate contains such low levels of the ingredients Piomelli identified that he doubts they have any effect.
Piomelli found that chocolate contains anandamide, which is also produced naturally in the brain and which activates the same target that marijuana does.
He also found two chocolate ingredients that inhibit the natural breakdown of anandamide, which could lead to heightened levels of anandamide in the brain.
A slightly more scientific description of that research is here: http://www.sciencenews.org/sn_arch/10_12_96/food.htm
I couldn't find a link to the Nature article itself (nor any peer reviewed research from them) so far, but the above-mentioned Nature article is:
Nature. 1996 Aug 22;382(6593):677-8.
Brain cannabinoids in chocolate.
di Tomaso E, Beltramo M, Piomelli D.
In summary, Yes, chocolate can produce effects similar to marijuana, but the magnitude is significantly lower which is why OP (or the answerer for that matter) don't notice any effect.