Any stories (serious and/or anectodal) on transitioning to a one
seater appreciated :-)

Unfortunately, checklists are not prioritized, and often
get so long that the really important things get muddled
over.

1. Make sure the airbrakes are locked

2. Have it trimmed for takeoff at your C.G.
(and too much nose down is better than too much nose up)

3. Lift off at sufficient flying airspeed (don't be too quick
to leave mother earth).

4. ETC, other stuff...

In any new aircraft type glider I fly, I look up the
accident records first. The most common accident causes
tell me how to prioritize my checklist, rather than just
having 22 equally important checklist items
(air vent closed? C'mon). Then I go and cut down the
checklist, eliminating some "niceties" that aren't on
the POH checklist but somebody threw in anyway...