Awwe, poor big brother G-dog, being lonely is no fun, I would totally build legos with you!
I'm sure Auz isn't that different than Canada, here we have a mentorship program called big brothers/big sisters where you can volunteer some of your time to connect with at risk youth in need of a part time role model or just someone to hangout with and talk. Maybe that could fulfil your heart's desire of sharing wisdoms with little-ish ones that will need it and may not get it otherwise and who doesn't like legos!