I blame the new bike bag, really. It’s lovely and waterproof and oh-so-practical – a Real Bike Commuter bag – but it needs to be packed differently than my old bag. Which means I need to remember different things when I’m getting ready to leave the office. Which means I wasn’t thinking of where I left my bike helmet when I flew out the door the other day.

I didn’t even notice until I was a block away from the Hawthorne Bridge. I looked up at the clouds to check if I would beat the rain, if I was likely to need my hood. My head felt lighter than usual. Traffic was louder. The first wave of panic was immediately overrun by resignation. Of course I forgot my helmet.

I thought about turning around and going back to get it, but I was already running late. I know exactly how long it takes to bike to daycare – 24 minutes on my heavy cargo bike – and I didn’t have time to get back, grab the helmet, and bike the 4.2 miles uphill before daycare started laying late charges on me. So I kept going.

The whole way there I felt people’s eyes on me, judging me, this reckless woman biking in traffic at rush hour without a helmet. Every time I passed someone, or was passed by someone, I wanted to explain myself: It was an accident! I always wear a helmet! I follow the rules – I am a rule-follower!

I thought about the bad example I was setting for my kids, who are never under any circumstances nuh-uh no-way allowed to get on their bikes without helmets, even though I never wore one when I was a kid, and why is it so bad, anyway, for a kid to ride his bike on the sidewalk without a helmet? Are sidewalks any harder now than they were when I was a kid?

I wanted to like it, this unexpected moment of freedom, of feeling the wind in my hair. Instead, I felt vulnerable in a way that had nothing to do with the chance of cracking my head open on the pavement. Like I was letting the stares of the cyclists around me define, just for a moment, what kind of person I am. Foolhardy. A bad example. One of those cyclists that give other cyclists a bad rap. A daredevil. I ducked my head and focused on the road.

When I got to daycare, I made sure to tell my kids that Mama made a mistake. I promised to be extra careful on the way home. They were unimpressed. I reminded them that it wasn’t safe to ride without a helmet. “We know, Mama,” the 5-year-old sighed. Mostly they wanted to know what was for dinner, and which one of them would get to tell M that Mama was a sillyhead. Another way to define me, I suppose.

On the way into work this morning I saw a guy on his 10-speed, sans helmet, weaving downhill in and out of traffic with both hands in his pockets, and I thought: Idiot. What is he thinking? And also: Man, I wish I could do that.