What I regret most about being willing to do this though is that I made life difficult for fellow engineers. Everybody who unquestioningly puts in long days makes it harder for somebody else to actually keep decent hours. (And you'll want to go there at some point - see above)
There are plenty of places that have good work hours, and most places that don't have crappy engineering practices on top of everything else. So if you want to do your future self a huge favor, don't sell yourself via "I can work insane amounts of time". What you'll get for that - if you'll get anything - is a crappy job at most likely a crappy place that you'll quickly come to hate.
Sell your skills instead. Or, if you actually love working 16-hour days, strike out on your own. At least then you're not working to line somebody else's pocket.
I've never interacted with an old and dying man or woman whom would've said anything similar.