I love cycling, I go out as much as I can with my routes between 60 and 120km. A few days ago I cycled to Burlington, ON, 135km round trip total as a crucial point in my route was closed. (Princess point in Hamilton) A big detour on the fly in an unfamiliar city added a lot of km.
I only cycle from spring to fall, it has to be above 16c for me to go out, otherwise I'll go jogging, I don't like my hands cold nor breathing cold air at 25 to 30 km/h. (Jogging in snow is fine though) Still that's plenty of time in the year to rack up 3000 to 4000km. I don't have an odometer but know the length of my routes, google maps is very useful for planning or figuring out where I was. This week I've done over 300km, so it could even be more than 4K.
I spend about CAD 400 a year on my bike, maintenance, replacements. I need a new chain and new tires every year, go through a bunch of inner tubes, patch kits. I always take a spare inner tube with me as well as a few tools for repairs on the fly. I get about 6 to 8 flats a year. Pretty much everything besides the frame and saddle have been replaced on my bike over the years. (I've had this bike for 12 years or so) It's a Specialized Crossroads bike, at least the frame is.

That's the original version. Mine has race pro wheels now, different front fork, grips, pedals, gear switchers etc.
I take my kids along sometimes. They both used to ride along in one of these.

It's quite a bit of extra weight to pull, 30 to 40km max before they get too bored although they usually fell asleep along the way. Now the oldest is on his own bike which is just more work for me as he makes me push him most of the way lol. That trailer has seen a lot of mileage too. I already had to fix a broken axle and tears in the windows (from sleeping against it with a helmet on)
Today I'll probably take them to Glem Morris again, play in the river and stop by the park and splash pad on the way back. One of the advantages of having kids, you can use a splash pad to cooldown without being looked at like a creepy old dude.