When I had one bike, things were peaceful. But then one day that bike had a problem and had to commute on the train. That me thinking about a backup bike.
A second bike was added as a backup while I continued using the first bike. Then one day, the first bike had another problem so I used the 2nd bike. But I didn't fix the first bike and one day the 2nd bike had a problem so I had to commute on the train. This gave me two ideas: firstly, I should fix those two bikes, but just in case both bikes had a problem in future, I would need a third bike.
And then I realised it wasn't a problem with the number of bikes. It was a problem with me. And so, if iced the problem with me but I kept the bikes!