[charlie0]

It isn't true at all mentoring takes a lot of effort. It really depends on a lot of factors. My 2 bosses at work are excellent at abstract thinking and mental models. They are usually able to provide significant ways of looking at things differently in just a few minutes of talking with them.

I will say they are hard to find. These aren't your average people.

It also really depends on where the mentee is. If there is a massive gap from where they are and where they want to go, that would be a large undertaking.

However, mentors don't have to expend all that effort. Even just a bit of help from time to time would be preferable to zero mentorship, which is where most people are today.