The phrase "like an absent-minded professor" refers to someone who is forgetful, preoccupied, and perhaps even a little bit disorganized. To find antonyms for this phrase, we can look for words that describe someone who is sharp, focused, and on top of things. Antonyms include terms such as "alert," "attentive," "conscious," "mindful," and "observant." These words suggest the opposite of absent-mindedness and imply someone who is fully engaged and attentive to their surroundings. Other antonyms might include descriptors such as "organized," "systematic," "meticulous," and "detail-oriented." By focusing on these opposing qualities, we can better understand the full range of traits that are associated with being an "absent-minded professor.