Joseki variations are not explored enough

In countless games my opponent has defended the playing of a joseki rapidly as legitimate because 'it is joseki'. They forget that they are actually playing just one of a number of joseki variations. Their habit speed fixes their potential to that single joseki from the initial starting position.

Additionally, they will still play the same joseki variation regardless of the layout of stones near to that corner. Joseki is conceived to be locally optimal, but that can be undermined by proximate stones. Often, a joseki variation is selected to secure the corner by default. By pausing and properly considering the stones outside a corner, you may choose to bypass joseki, concede the corner and gain more outside in influence or moyo than is conceded inside the corner.

The gravity of knowledge about joseki, along with the gravity of a easy corner territory blinds players to possibilities outside the corner.

A valid argument can be offered that only one joseki variation has been learnt and that it is hard to learn more. But you can study joseki without learning. Better by far to understand why each move in a joseki is optimal than to learn these moves mechanically. Then you can explore joseki variations in the middle of live games that you have not learned by adopting that spirit of optimal play even if the exact moves are not memorised. It will, at the very least, strengthen your reading muscle.

One of the habits of professional players that confuse amateurs is that they will sometimes leave a joseki incomplete. They choose to tenuki. So those who are stuck with a rigid joseki mindset miss out on this possibility also.

The classic example is to tenuki by ignoring a 6-4 approach to your 4-4 stone. You can survive a second attack on that stone, so locally you are compromised but have not lost too much. Remember that the 4-4 stone is not optimally placed to secure the corner in the first place.