how to never mix up 在学 and 薬学 again

If you keep failing 在学 because you confuse it with 薬学 like a casual, here is your exact fix. Step one is locking in a 15-minute SRS interval immediately after your first failure. Step two is force-linking the 'zai' in 在学 to 'present' and 'yaku' in 薬学 to 'medicine' using an isolated card pair. Step three is running this exact loop five times before sleep. It works every time if you actually follow the system.