Not sure if this is broad enough to count, but playing through FFX when I was younger I could never ever figure out how to do Lulu's Overdrive. For anyone who hasn't played Final Fantasy 10, essentially when characters do or take enough damage, their overdrive bar fills, allowing them to use a very strong ability.
Activating these abilities generally required you hit the correct buttons on your ps2 controller or have very precise timing. In the case of Lulu, her overdrive required you spin the right analog stick enough times to build up power.
As a child, I could never figure it out. Went through the whole game being unable to use Lulu's overdrive, and with her being the prime magic damage dealer in the group, I missed out on quite a fair bit of damage.