I spend a fair amount of time mentoring younger founders, and I should admit something that probably undermines the whole noble premise: I am almost certainly getting the better end of the deal. I started doing it to give something back, which is the respectable reason everyone offers. I have kept doing it because I learn more in those conversations than the people I am supposedly teaching, and at some point pretending otherwise felt dishonest.
The phrase "mentorship is a two-way street" gets used so often it has gone soft, so let me be specific about what I actually mean. The founders I advise teach me things I genuinely could not learn any other way, because they are standing somewhere I cannot stand anymore.
They can see what I have stopped seeing
After enough years, you accumulate a kind of expensive blindness. You know how things are done, and that knowledge quietly closes doors you no longer notice are there. A founder two years into their journey has not learned yet what is supposedly impossible, so they routinely ask the question I have been trained not to ask, and often it is the right question. Half the time my honest internal reaction is, I have no idea why we don't do it that way, and I have to go find out.
They are also closer to the current ground truth than I am. They are using tools I have not had to learn, hiring in a market I last saw years ago, and reading the present rather than remembering the past. I get a free, continuous education in how the world actually works right now, in exchange for opinions I would happily give for nothing.
I started mentoring to give back. I kept doing it because I was quietly learning more than I was giving, and it felt rude to stop.
What I try to actually give
In return, the useful thing I can offer is rarely answers. It is pattern recognition and perspective on time. I have made many of the mistakes they are about to make, so I can sometimes say, gently, that the thing keeping them awake will not matter in a year, and that the thing they are ignoring will. I cannot make their decisions, and I try hard not to. I can occasionally widen the lens. Some of what I have learned about staying composed is most useful precisely when handed to someone in the middle of their first real crisis.
Why I keep the door open
This is not so different from how my co-founder and I keep each other honest. The value comes from the friction of a different vantage point, from someone who is not trapped inside your assumptions. Young founders are not a charity case I tolerate out of duty. They are one of the best ongoing sources of fresh thinking I have, and the day I start believing I am only the one teaching is the day I should probably stop, because I will have stopped paying attention to the better half of the conversation.