I believe this is an individual issue dependent on discipline, personal tendencies and personal awareness.
I played strictly for fun and recreation for years and blew plenty of money doing so but viewed it as entertainment and never bet more than I could afford. With that I am pretty well disciplined. Regardless if at the casino or online.
I view the potential to make a living playing poker at a bit of a crap shoot for myself and never put my mortgage, rent or necessities at stake. But I am in it for the long haul. The more I learn about Poker the more I apply it as a philosophy of life. Hedging your bets is key keeping a +EV is helpful but not necessarily profitable in the moment, but I believe it will be over the long haul.
As for being good enough to be a pro I think this would have been easier in my 20s and 30s, even my 40s when I had the stamina to grind for 10-20 hours at a time. But back then it was much more profitable for me to work and make a decent living doing my job, so never considered taking the plunge (It would have admittedly been a disaster if I had lol).
I put my health first so if money is at stake I do not play unless I am well rested and in good spirits. I have found I do not do well if I am in a funky mood so I don't force it at the casino. If I am online I will give up if not feeling well so I can lie down when I need to even if in the middle of a tourney.
Not sure if I answered the question properly but that's all i got !