Trauma can cause memory loss. Sometimes the memories come back a very long time later, sometimes they don't. It's kinda like whatever you are going through in combination with physical injuries you are receiving just turns off the tape recorder in the brain.

For the OP -
Are you crazy for wanting to get back on a bike? No. Biking is fun. (This is being said by a person who hates every form of exercise.)
Are you crazy for wanting to get back on a bike so soon? Oh heck yeah, your papers certifying you as crazy are likely already en route in the mail. I can testify to the fact that pushing yourself after injury will make the healing process slow to a crawl and can create chronic issues that wouldn't exist if you just sat on your butt and rested. Plus, people are not made out of a cookie cutter and while 6 weeks is a good average, your particular set of bones may need 12 weeks. Or longer.