Sometimes, you may hear about a tech guru telling how good he's using a specific technology or language and will try to force everybody to use it. This is a clear warning for me.
The reality, in Computer Science and Software Engineering, the more you know about something less is the understanding feeling. This is a process I describe using this simple chart.
You start getting more knowledge, you'll become more confident, but at some point, you have enough knowledge that you may realize that same as Jon Snow, you know nothing :).
Isn't bad to tell about how good u are, but forcing other people to use your methods or using your knowledge to undermine others' opinions in a bad way is just very bad. This is very common when you have a guru-tech-boss and he doesn't allow anyone to question him or think differently.
Don't be that guru-tech-boss, don't stay close to those people. If you find one, probably he isn't an expert as he tells.
Just keep learning.
When someone asks what tech should be used, a real senior answer is depends