What have you owned that upon reflection, you have thought, "What a stupid prick am I for that misguided purchase".
For me it was my RG250.
When i bought it the last owner told me it was "done up" a bit but when it made its first trip to the shop the full extent of the dramas began. It had been bored to within an inch of its life, ports you could walk through and jets in the carb that would rival irrigation fittings for flow rate.
This was my first road bike and it was just a little tempremental. Heaps of fun when on the pipe but a bitch in traffic and almost impossible to pass the learners shit that NSW imposed 1 week before my P's test.