Hey Jason, my kids didn't sleep much in the stroller or car either. Or at least, not when we wanted them to. But otherwise, their sleep habits are pretty different. The oldest used to wake if you dropped a feather, and until we got sick of it and just let him cry it out, he wouldn't sleep at all unless he was rocked and held. The second wouldn't sleep unless we left her alone, and the third requires a bottle to sleep. Let us say that the second is the easiest child to deal with, sleep-habit wise.
So yeah, David, all kids are different, and you're going to get a LOT of advice over the next, well, 20 years. Try to take it all with a grain of salt. Including this advice.
I didn't do it, no one saw me, you can't prove anything.