Here's the psychology I see of it in my family.
My brother has no imagination, poor social skills and loves to pontificate. He cannot abide people that he deems peers or inferior to be better at things than him unless they are crazy better like a mate is a professional athlete and beats him in an informal race.
If I mention I have taken up the guitar and chatter about what I'm enjoying about it, he will think "oh what a brilliant idea. I'll try that." Then he will obsess over all things guitar for weeks. It is clear that he cannot bear for me to be better or know more. He sprints to be superior. Then he will call me to question my methods, goals, gear choices, all in a friendly chatty way but still. I realised in our thirties that it was continuous lording it over me, you know to help me to do better. Even before he gets better than me he will research methods of learning and call me to explain how I did it wrong. All in the kindest most supportive tone. That also brooks no dissent. All joy is sucked out of it for me.
DH noticed it before me, years ago in a random comment that shocked me after a visit, Looks like you can't have nice things for yourself Tork Why didn't you tell him to fuck off?
Well, I can't say "No brother, you may not learn guitar! I own it now." That's not how life works. I knew I would be unreasonable to tell him not to do it. So I thought the problem was in my own head.
He frames every conversation as friendly, helpful, wanting to be enjoying the same thing as me, you know bonding. So, of course I felt I was a cow to be annoyed at it. DH pointing out DB's obvious joy in lording over me, benevolently, helped me see why it pissed me off.
FFS he even started buying the same household appliances as me then told me either (a) they weren't as good as expected or (b) how to maintain them properly.
It's not just me. If his children join a club he becomes a leader (even taking classes to qualify). If they don't need a leader, he will take the adult classes. If they become good at say, line drawing, he will watch all the youtubes and practice obsessively until he is better and can teach them.
Everyone tells the kids how nice it is to have such involved parents. Kids have to smile and nod.
Anyway, it would seem petty and churlish to say anything to him so I don't.
I did have a joke about it with my other siblings and their partners. They were v helpful pointing out that DB does it worst with me and with his kids but others get it too. Siblings take the piss a LOT, also help me to steer conversations away from what could be spoiled, which makes it much more bearable.
Other brother even had a word about letting children have their own things, their own space away from parents and something they are expert at. He seemed to get it. He investigated lots of things about child development then helped us to know more so we can all do better 
. FFS. No point talking to some people.
Crack on DB, I'll be over here planning my foot tattoos.