You are missing part of the equation.
Mashing it opens all the resin glands and combined with a bit of heating it, aids the process of what would be done in extremely long curing, turning much much more of the cbd's and other cannabanoids into thc. Make pure bubble and do it right it should be better than the keif it came from and last longer by weight as long as it's not too old. Once you have made it all thc it does start to slowly degrade. Really old hash is less potent than it was fresh.
Changing the ratio of thc vs cbd vs other cannabanoids changes the high also, not just intensity. Here is a list I found of the difference major cannabanoids and their effects:
The Active Ingredients Of Cannabis
Cannabis products include marijuana, hashish, and hashish oil.
THC (Tetrahydrocannabinol) gets a user high, a larger THC content will produce a stronger high. Without THC you don't get high.
CBD (Cannabidiol) increases some of the effects of THC and decreases other effects of THC. High levels of THC and low levels of CBD contribute to a strong, clear headed, more energetic high.
Cannabis that has a high level of both THC and CBD will produce a strong head-stone that feels almost dreamlike. Cannabis that has low levels of THC and high levels of CBD produces more of a stoned feeling. The mind feels dull and the body feels tired.
CBN (Cannabinol) is produced as THC ages and breaks down, this process is known as oxidization. High levels of CBN tend to make the user feel messed up rather than high.
CBN levels can be kept to a minimum by storing cannabis products in a dark, cool, airtight environment. Marijuana should be dry prior to storage, and may have to be dried again after being stored somewhere that is humid.
THCV (Tetrahydrocannabivarin) is found primarily in strains of African and Asian cannabis. THCV increases the speed and intensity of THC effects, but also causes the high to end sooner. Weed that smells strong (prior to smoking) might indicate a high level of THCV.
CBC (Cannabichromene) is probably not psychoactive in pure form but is thought to interact with THC to enhance the high.
CBL (Cannabicyclol) is a degradative product like CBN. Light converts CBC to CBL.
If you are a grower, you can experiment with different strains of cannabis to produce the various qualities you seek. A medical user looking for something with sleep inducing properties might want to produce a crop that has high levels of CBD.
Another user looking for a more energetic high will want to grow a strain that has high levels of THC and low levels of CBD. In general, Cannabis sativa has lower levels of CBD and higher levels of THC. Cannabis indica has higher amounts of CBD and lower amounts of THC than sativa. See marijuana
strains.