Here's my own journey, from 3 years ago to today:
3 years ago (Top speed, <30 mph, it was a mess!):
2 years ago (first non-kit build, I still didn't really know what I was doing, got gearing all wrong, used an aluminum frame which lasted about 2 months, etc. Top speed 36 mph or so.)
My current ride (first built 1 year ago, picture shows more recently improved version, top speed, 41 mph) :
And finally, my current project (at this point I am basically building a motorcycle, top speed, 70 mph):
Well, that was a fun trip down memory lane. I've certainly come a long way.