How often do you fly?
At the moment, pretty frequently for a private flyer -- X2-4/week, weather depending. And in a Super Cub only, which is a very simple aircraft, even though it has an electrical and vacuum system, which many don't.
However, all the stuff is there in front of you in most basic light aircraft. You should be able to start it without a checklist, then check after start-up that everything's OK, then taxi off and when it comes to the run-up, well you should be able to do that without the checklist and then if you do a cockpit left to right check for your pre-takeoff vital actions that's pretty much it, isn't it? Your checklist consists of the knobs, switches and instruments by the side of and in front of you, along with that big waggly thing in your hand (the stick, that is) and your seatbelts and door latch.
Sure, if you don't fly frequently or it's a complex type, perhaps a checklist may be useful, but I'll continue to be a devil's advocate here and suggest -- mischievously, of course -- that if you get into a light single and it's so unfamiliar you need to be using the written checklist, you should go for a checkflight first with either an instructor or another experienced pilot and not just trust to a checklist to refamiliarise yourself.
Interesting debate, and I suspect no-one who has taken part in it has changed their positions one jot. Fun, nevertheless.
QDM