EVERY FUCKING DRUG IS A GATEWAY DRUG.
Weed -> Ohh, lets try some shrooms now! -> Ok well i did shrooms, it must aight to snort a couple lines -> ohh yeah im lovin this yay, so smoking crystal must be even better! -> crack -> heroin.
Now not many people get to that final line or whatever, but "real" drugs (marijuana is a vitamin to me) are about progression and going further and further.
Who cares where it starts. Weed is the best.