envy or better enviable + [commendable adjective] would get the point across in your title question. They express that the person mentioned has something good about them that you do not have to their degree.
I would choose"enviable" as opposed to "I envy" as envy has a sharper edge of jealousy to it and using "enviable" is more saying "the typical person would envy"
enviable from Cambridge online dictionary.
adjective US /ˈen·vi·ə·bəl/
(esp. of a quality or advantage) causing you to wish that you also possessed it; desirable:
She has an enviable ability to work under pressure.
In the example above a very generic "ability" is chosen
To go further, one can choose an adjective of a trait that is more a matter of special "character" rather than merely luck ( i.e. enviable compassion vs enviable good looks ) that further softens the "envy" into more of a 'aspiration' than "greed"
Your Example: your examples were specifically about the forgivingly noble ability to put things behind and focus on the task at hand.
I would suggest one of these two words for your particular example
Magnanimous at oxford living dictionaries : magnanimous
ADJECTIVE
Generous or forgiving, especially towards a rival or less powerful person.
‘she should be magnanimous in victory’
- Bob had an enviable magnanimity
or
Gracious at Oxford living dictionaries: Courteous, kind, and pleasant, especially towards someone of lower social status. ‘a gracious hostess’,
‘Greig was gracious in defeat’
- Bob was took an enviably gracious approach ...
If you wanted to focus more about their field specialty, perhaps "professionalism" or "enviable intractability from their pursuit of knowledge(or justice, law, medicine etc)"
While you can choose to get long in your descriptive approach, it would be "enviable" that is perhaps the word itself you are looking for, coupled with words that elaborate to the degree of focus you might choose on a given field"