Dosage: How much is too mush
With all things in life, it is better to start off with less and work your way towards more. The rule of thumb is you can always eat more, you cannot eat less however. Remember, it is always better to play it safe than to be sorry.
Sometimes to know your own personal limit, you need to have that experience where you do too much. Just apply the same concept to drinking alcohol for any of us who are acquainted with the horrible feeling of a hangover. With any substance, there is a threshold of enjoyment before we crossover to a point of miserable return. With experimenting over and over again, we gain experience. With confounded experience and awareness, we are knowledgeable.