This is hardly a new sentiment in the world of sports.



The bemoaning of late-won wisdom. Mistakes made. Harm done. Damage accrued. All via hindsight.



The old, if-only-I-knew-then-what-I-know-now spiel.



Which you’ve heard before – typically from a player freshly retired or, occasionally, from one making a last gasp at athletic relevance.



Not on this morning.



Delivering the sermon of regret is a slender young fellow. Ball cap on backwards, baby-faced, exceedingly polite, unflinchingly earnest, uncharacteristically talkative. Only 23 years old.



Yet nevertheless vowing to do better.



“These surgeries were an eye-opener for me,” Sean Monahan, the Calgary Flames centreman said, who, after his season was shut down, endured four – yes, four – operations to fix his left wrist, left and right sports hernias, and right groin. “I came into the league … and it’s kind of flown by...