A few observations from your initial description to maybe help you figure out how you want to handle this.
1. Most people calling the helpdesk are in a very specific state of mind: they have a problem and they want it solved. They're not curious about where the problem comes from, they don't want to know how to avoid it next time, they don't want to learn a better way to do things. They have an interrupt that prevents them from resuming the rest of their day, and they want that interrupt dealt with as quickly as possible. For people in this frame of mind, trying to be helpful usually backfires. You solved their problem, that's what they called for, they're not interested in getting educated. These people will always look for the fastest way to solve their problem and the one which requires the least amount of cognitive activity on their part. Anything that makes the conversation longer than it needs to be or requires them to engage more brain cells is a downside.
2. It seems like there's a status issue as well. You mention that these users "operate beyond [your] abilities" so maybe a bit of inferiority complex on your part? In which case explaining how you know better than them could be a way for you to even the score, so to speak. But then this triggers its own opposite reaction, "I have a PhD so of course I can figure out how computers work if I put my mind to it, stop talking down to me". To which you respond, effectively, "having a big brain and knowing how things work are 2 different things, you may be book smart but I am street smart" and it escalates.
My advice, insofar as it makes any sense, is to let go of all this social context when you're in helpdesk duty. Take the call with the objective to help a human being get on with the rest of their day with as little fuss as possible. Accept that some will be grateful and say thank you, and others will be douchebags, because that's how human beings work. Trust to karma to reward the good ones and punish the douchebags. Accept that you can't teach someone who doesn't want to learn. Don't bring your ego into it, because winning technical arguments with someone shouldn't be how you measure your self-worth.
1. Most people calling the helpdesk are in a very specific state of mind: they have a problem and they want it solved. They're not curious about where the problem comes from, they don't want to know how to avoid it next time, they don't want to learn a better way to do things. They have an interrupt that prevents them from resuming the rest of their day, and they want that interrupt dealt with as quickly as possible. For people in this frame of mind, trying to be helpful usually backfires. You solved their problem, that's what they called for, they're not interested in getting educated. These people will always look for the fastest way to solve their problem and the one which requires the least amount of cognitive activity on their part. Anything that makes the conversation longer than it needs to be or requires them to engage more brain cells is a downside.
2. It seems like there's a status issue as well. You mention that these users "operate beyond [your] abilities" so maybe a bit of inferiority complex on your part? In which case explaining how you know better than them could be a way for you to even the score, so to speak. But then this triggers its own opposite reaction, "I have a PhD so of course I can figure out how computers work if I put my mind to it, stop talking down to me". To which you respond, effectively, "having a big brain and knowing how things work are 2 different things, you may be book smart but I am street smart" and it escalates.
My advice, insofar as it makes any sense, is to let go of all this social context when you're in helpdesk duty. Take the call with the objective to help a human being get on with the rest of their day with as little fuss as possible. Accept that some will be grateful and say thank you, and others will be douchebags, because that's how human beings work. Trust to karma to reward the good ones and punish the douchebags. Accept that you can't teach someone who doesn't want to learn. Don't bring your ego into it, because winning technical arguments with someone shouldn't be how you measure your self-worth.