For me, a bike was the fastest way to get around campus, and practically cost me nothing as a broke student 😅
From there I ended up going on progressively longer rides for leisure, getting to know how long I can ride before running out of steam. Now I’m pretty comfortable commuting by bike - for longer distances though I tend to take public transport
I’ve been using my bicycle as my main form of transportation since late 2019, when I had just recently moved into a tiny dorm room and had independence for the first time. I was put off of learning the bus system at the time because uncertainty about employment made me hesitant about even a $2 fare and the routes I would need to take before the 2021 systen redesign were significantly slower than biking. That, along with not really knowing many people at the time (for carpooling), meant I pretty much had to bike everywhere, putting up to 30 miles a day on the bicycle depending on what I was doing. Thankfully, I already had the leg strength from years of purely recreational biking.
Since then, I usually only pick the bicycle for trips of up to about six miles in length (per direction), plus or minus a couple miles depending on how suitable of a route I have for biking. The majority of my trips fall within that range. Anything longer than that or any trip where I need to bring a ton of stuff with me and I’ll take a bus, train, or carpool to my destination. The end result is that I went from thinking “I’ll get a car once I get situated” to “I don’t need to get a car for the forseeable future”.