Very similar impressions after years of biking (and having switched to an E-bike about 2 years ago).
I bike year-round in Warsaw, Poland, even though most people consider winter to be "off-season". Don't really understand why — they do go skiing after all, so cold must not be the problem? The only days I don't bike is when it's raining heavily or when it's really slippery (lots of snow, freshly frozen sleet, etc).
There are days when I don't ride a bike, and on these days I can really tell the difference: I feel much worse.
I found that what I miss when switching to a car is the sense of freedom: on a bike, you can stop pretty much anywhere, while in a car you need to follow the road in the traffic and are generally stuck. No way to stop quickly, take a phone call, or admire the pretty passers-by.
Also, switching to an E-bike was a great idea: it doesn't take away the exercise (as most people tend to think), it just makes biking more pleasant and extends the max distance I can go. And in summertime I can set the assist to max and not worry about arriving all sweaty.
If you live in a city, I'd highly recommend getting a city E-bike. Not a mountain bike. A city bike with proper mudguards, upright posture, and a large basket in front. Don't be that guy in lycra pants on a mountain bike, with a backpack on his (sweaty) back, taking the full additional weight of the backpack on the narrow seat, and with a mud stripe on his back. Enjoy life!
