I run hot and cold when it comes to wearing a helmet. It’s not that I have any strong views on their utility one way or another, but sometimes I’m just lazy or I really enjoy putting on a ball cap or a headband better. The headband/bandana is one of those trademark habits from my rowing days, so I always have one available in the Pendel and find it ideal for keeping the sweat out of my eyes on hot days. The downside is that I have to explain why I have a wide, white stripe on my otherwise tanned, expanding forehead.
Part of it is also my current helmet. It doesn’t fit well and rides too high, making me look more geeky looking than I already am.
So my solution was to order the official geek helmet, a Bell Citi. I had been thinking on this for some time, and finally Nashbars holiday sale, where they had ones discounted from $50 down to $30 forced my hand.
It can’t be a real geek helmet without some obnoxious stickers of some sort, so that will be another project. No Sheldon eagles, but maybe some obtuse political statement, or an advert for the Central PA Bike Campers Association.
Pedalling Along 
My kids tell me not to get a City helmet, but it’s the one I am going to get anyhow. Like you I’m a 20% of the time helmet rider. Only on the Felt Road bike. I like my statement hats. Most of them are soccer related. Holland, Inter, Arsenal. A couple double as piss of the right statements. One says Cuba and the other is red with a large white crescent moon and star. (Turkey)
Ironically I just joined the local rowing club. We do Whaleboats but there was recently a scull club formed.