Yes and no. Would depend whether you are talking about fresher resin(hashish) or bong resin. There would be some differences.
It ultimately would come down to storage conditions. The THC would gradually convert to a different cannabinoid which would still get you stoned, but it would be the kind of stone that sits you back in a chair where you can't move as opposed to fresh, properly cured with lots of THC gives you that buzzy high.
For example, if you allow plants to be growing in less than ten hours light, your beautiful THC converts to give you that sit down and shutup stone. The same thing happens with old hashish.
The stuff in bongs has been burnt and had vertually all of the moisture taken out, therefore mould(fungi) will not tend to grow on it.
So as long as it is stored in a dry place, the only thing to be concerned with, may be insect excrement building up in the cone if left for too long.
There's probably a lot more to it, but you shouldn't ask too much at a time of a stoned person.