At the end of a meeting or conference, one is usually asked "What did you get out of this? What was of value?" A great question - allowing the organisers to tweak and improve to meet expectation and need.
And yet rarely are the participants asked "What did you bring of value to this session?"
Think about it. We usually show up, passively listen, hope to be engaged, and leave with - or without - our 'aha!' for our time. And yet we all bring ideas and perspectives that would take the source material and enrich it beyond the sum of its parts.
Yes, I know that not all sessions allow room for interaction. I say don't attend those unless your manager is making you! LOL
Most sessions - even if they were not aware of the need in the planning stage - will welcome participation and debate. We're not in grade 3 learning our letters; we're adults exchanging information.
However, like everything else, one must be able to articulate the value to act on it.
At your next mentoring session - see if you can identify an upcoming session and plan, in advance, what you'll bring to the table. Then bring it.