Riding early and singing to myself when no one is around. I can sing in the car, too, but feel freer out in nature, much like when I used to have a 50cc scooter and rode the back/side streets in Vegas. Freedom!

I'm a mental health therapist. I really need the ride to and from work just to clear my head. The commute is about to change quite a bit next week with a carpooling arrangement, so tomorrow and the next few days will be my last 11 mile rides to and from work. I'll still have a couple miles but it's not going to be the extended ride that I like.
As for what makes me happy when commuting, it's good manners of both cyclists and automobile drivers, but especially cyclists.

Making first tracks in the morning, especially the first snowfall of the winter.

Tail wind and bright mornings in the summer. When I worked as a courier (car) i needed the commute to leave the stresful traffic of a big city. I had to cross a bridge to get home and while riding the bridge to the island i lived on all the stress just left me. Great feeling.

Being able to commute to work by bike makes me happy. When I get to work after biking I feel awake....it's just a different feeling I get when I bike in rather than drive in.

When petrol hit 2.25$ per litre which is about 8.50$ per us gallon made me happy knowing my bicycle runs on leg power. :)

Beautiful morning, left from a different train station and then had some pretty fog on campus for my short ride to the office.
https://cimg2.ibsrv.net/gimg/bikefor...e76dbb3a29.jpg
https://cimg3.ibsrv.net/gimg/bikefor...ed68bbc12a.jpg

So many things. It's faster than the bus, and the money I saved in the first year paid for my bike. Because of the riding, days when I'm not commuting now I explore and have seen parts of Chicago I never drove to, found some nice neighborhoods, great parks, etc.

My route to work is beautiful (for a city) and peaceful, the first half through a lakefront park but on quiet roads so I don't fight either car or bike/ped traffic, just herds of geese. I can zone out, get some exercise, wake up in the morning or decompress on the way home. I can take the long way if I want and see something new.

I love the act of riding, even in my Frogg Toggs in the rain, and being originally from a lot farther north the winter cold doesn't bother me, either. On days when I feel like crap and have to force myself out on the bike, within a mile I feel great! I've never felt better since riding every day.