It might be interesting to find how long it takes to become uncomfortable with clipless pedals.

I've had the same pair of Shimano double sided pedals on my beater bike for at least 10 years. During that time they have gradually required more pressure to unclip. They even caused a tombay fall or 2 which I wrote off as user error. Finally this morning I installed a different set of 15 year old pedals from my "spares" box. What a difference! Why did I wait for so long?