When you eat weed, it is metabolized in the liver and the THC is gradually released into your body. It is not Delta9-THC at this point. I think it's delta 12 or something like that, so you get a different chemical once it's out of the liver. Not only can you get really stoned when eating weed, but it's a different high when eating. It's more of a body stone than anything.

When smoking weed, your body reaches a limit of THC it can absorb and that is 100% THC per smoking session. But when eating weed, that limit is much greater than 100%.

Well hope it helps

Peace