All problems are interpersonal problems
That's one of the eurekas I got from reading The Courage to Be Disliked, my favorite book of the year.

A broken glass of not a problem
Imagine you're having dinner with two friends. The place is fancy, the conversation is lively, and the sparkling wine keeps coming.
One of your friends tells a joke, a bad one. You laugh anyway, spread your arms, and touch something with your arm. You hear a clink, and then a crash before you realise what's going on. Oops. What used to be your glass is now shattered on the floor.
The cost of the glass is not the problem.
The problem is what your friends might think of you. "I'm not drunk", you might say.
The problem is how this might affect that friendly waiter. "Are they going to deduct this from his paycheck?", you might think.
The problem is how everyone around stops doing what they were doing and now focus on you. "Why don't they mind their own business", you might be tempted to say to them.
If you were alone... and if restaurateurs did not exist, nor friends, nor curious patrons looking at you, then it wouldn't be a problem at all.
"All problems are interpersonal problems" – The Philosopher in The Courage To Be Disliked, page 53.
To ponder
Have you encountered a problem other than an interpersonal one in your professional practice? I have not. That's why today I compiled a cheat sheet for you. This is based on regular practices I've learned over the years and which help me solve interpersonal problems.

Alberto