In 32 years I have had that happen 4 times.
#1 was a department head with enough knowledge to be dangerous. I had to tread lightly so I just made sure I gave him ridiculously proactive help to the point where it became tedious for him to figure things out and way more efficient to ask me.
#2 was a secretary. He was hopeless - spreading his bad habits around the department. In one instance, he fiddled around with a “problem” all day, totally aggravating the director he was “helping.” When they finally called me, I came down and fixed the problem in seconds because I KNOW WHAT I’M DOING. The Director got so angry at the time she wasted all day that she threw ME out of the office. Of course I didn’t know that any of this had transpired so I was flabbergasted when she tossed me for fixing her problem. This secretary was the pet of his department head who liked having such a “knowledgeable” person on staff.That meant I couldn’t reign him in. I resorted to praying that he got a better job - which he did. He left 20 years ago and I’m still struggling to un-teach the garbage he taught his co-workers.
#3 was a maintenance guy who liked computers better than he liked doing maintenance stuff. He was constantly in someone’s office “working” on their computer. It was maddening. Finally our network moved past his skills and he got caught by his boss.
#4 has me stymied. They hired a secretary a month ago who said she worked in IT in a help desk position. Three higher ups have decided she’s going to be my backup for vacations or when I’m swamped. They came up with this grand plan on the basis of the interview. They have no idea what her skill level is nor did they let me test her or probe her knowledge at all. When I researched the “IT Company” she worked for, their annual revenue was very small and they only had 2 employees – presumably her and the owner. I am left to wonder if they only had one customer or not many customers so it makes me worry about her skill level. (And, they went out of business a couple of years ago so I can’t even check her references.) Thus I have no idea how much experience she actually has. I told my 3 bosses that I can’t train her until she learns her actual secretarial position first so I’ve given myself a 6 month reprieve to learn about her IT skills. So far, she seems comfortable with tech but so do others in her age range. The real problem is that her boss is the type of guy who has their secretary do EVERYTHING for him. I don’t think in reality he will be keen on me taking her attention away for example if I go on vacation for a week. My immediate supervisor wants me to hand routine tasks to her. I don’t have routine tasks anymore. When I did, it was stuff like swapping tapes in our long-since-retired tape backup system. Now, I’m pretty much working on new projects or answering help-desk questions. My day is always different. This new setup is a shame because our managed services provider was my backup. In the 5 years they’ve been my backup, they’ve only had to answer 3 calls. It was wonderful. When I had other internal staff serve as my backup, users were so rough on them they got physically sick leading up to my vacation time. This happened to 3 women who served as my backup. Two of them were the toughest, most confident women I’ve ever met and users gave them stress induced IBS. They never tried those shenanigans with the managed services company.
So, aside for talking to your problematic user’s department head, praying he or she gets a better job elsewhere or giving such stellar support co-workers turn to you instead of this user, I guess I’m in the same boat as you with no real answer.