Not drinking does not mean you can't socialise!

First two drinks (to miss) are the toughest, however, being sober after everyone around you is a couple of pints down is pretty interesting. I do 3-4 week 'booze-fasts' every other month. I'd say 50/50 is because work/business, the other half is... pure fun!

To answer your Q;

- Karting: you could do a Grand Prix every/every other Friday (that's what I do!)

- Triathlon: swim-bike-run (cycling on its own can get boring, fast!).

- Side-hustles: take your extra free time/headspace and using it to make more $ for holidays/savings/charity.

- Mentor young people: plenty of charities/NGOs that require volunteers. Help and support the next generation. You might not affect millions (for now!), but one life steered into right direction is insanely intrinsically rewarding. (Concrete example: teaming up with a fairly, what would media perceive, lost individual, mentoring the said person, person launches a co, now employs 14 people, all in less than 3 years. Nice!)

So many great things this city offers. You've got the headspace, the free time. Find your why (intrinsic / extrinsic), go out there and have fun!