Brief Answer:
really good question

Detailed Answer:
There is high variability in marijuana. both in the particular effect of the marijuana itself and additionally, other contaminants intentionally or unintentionally added to it. Common pesticides do exactly what you described. It is a common effect.
The context can cause the identical drug of any kind to have different effects. If you are having a bad day and take an aspirin, it can cause stomach irritation and bleeding when it never did prior. As an example. The drug can interact with other conditions (dehydration for example) other medications (any depression medicine for example), or other circumstances.
Oh, right, and people develop immunity to things. Heh, forgot about this one, and it's probably the most important of the "other circumstances". This can involve allergies. This can give the symptoms mentioned. It's pretty common with marijuana. It would stay around forever once it develops and can cause even severe breathing problems (asthma). Surprisingly we don't see many ER visits for it when more than 10% of marijuana smokers get some lung reaction to it.

You had two questions the later is really really interesting since there was a landmark article on memory I saw yesterday that you just proved wrong.
It said there are two memory systems going through the standard thinking part of the brain that go short remembering and long remembering. This is correct BUT they aren't the MAIN two memory circuits which are thinking and feeling.
Feeling memory is at the base of the brain, involved in the circuits that involve emotions and also all drugs of abuse and is NOT mainly in WORDS. YOu eat something bad, you do something that produces pain, and you IMMEDIATELY form a response memory that you have for a long time. Something (likely NOT psychological) happened with taking marijuana. A reaction to ANYTHING will trigger an emotional memory that stays for a long time. I have this to electrical sockets and bats. The wife has this to eggs and smores.

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Brief Answer:
hard to say

Detailed Answer:
Ok, if someone had Even the smell of it gets me paranoid and I start feeling the symptoms again " to strawberries, would it be prudent to have strawberries again?

You'd wash them really well, have benadryl or steroids handy then try a small amount of them. You might try small amounts of marijuana in a different form than you previously had it. Without the smell, there will be different contexts and the same psychological issues won't likely arise. The same allergic responses WILL, so, having treatments available might be a good idea.

But then if brownies do not trigger a reaction then is smoking it ok? Probably but there can still be reaction to the lung by PHYSICAL EFFECTS of smoke even if there is not an allergic reaction. This can be made less by making the smoke less irritating if it should occur. Hookash or other tools MIGHT be helpful (but they are not guaranteed to work).

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