David Brooks ought to forgive himself. The kind of radiant people he justifiably admires are exceptional people, like Einstein, Gretzky, Mozart, or Shakespeare, in their respective fields.
The quality he wishes he had, like every human quality, is governed by the normal curve. Some people will be very deficient, some people will be greatly gifted, and most will be, plus or minus, clustered around the average.
The fact that he (and I) can see the pinnacles of radiant goodness, and appreciate it, means he is already above average in this quality. But very few people will ever achieve that, like very few can score 90 goals in an NHL season or write the next Hamlet.
Normal people, those close to the average on the normal curve, can only do the best they can. We ought to also admire those who, through effort, do a little better than their natural limitation.