How to switch to a different framework, change the team and not go crazy

At the BoF, in contrast to talks and roundtables, there is no division into participants and presenters: here everyone interacts with each other as equals. The main thing is not to off-topic and discuss the topic.

Switching to a new technology stack - dream or reality? Let's discuss what's the best place to start: learning about current technology or boring basic theory? How best to answer questions about another stack at a job interview and not burn with embarrassment? And how to "refresh" knowledge of a long forgotten programming language?