I may find myself debt-free at 40! I'll be 40 in the next year, regardless, and I got rid of consumer debt (including 0% car loan) about 4 years ago. I just got rid of a debt to myself, having borrowed from my RRSP as a first-time home buyer. Even more recently, in the last couple of weeks, I paid off the last $5k of my student loan. I had been making the payments without acceleration and could have continued paying for a good, long time, but what eventually got to me was the logistics of having an additional bank account from which automatic payments could be made (and taking the time to fund the account properly, to keep a balance of $2.5k to avoid banking fees). So I paid it off! And I'm quite happy about it!
So all that's left is a mortgage and my house is up for sale. I am planning on moving in with my boyfriend, while he renovates his house and then puts it up for sale. During that period, I would be debt-free. Our plan, though, is to then buy a house together so I would likely have another mortgage at that point. Though if we stay at his place long enough, we may be able to get our expenses low enough that I could save enough to not need another mortgage when we do buy...
So it may happen that, coincidentally, I will be entirely debt-free on my 40th birthday, which I would really like as a symbolic milestone. But, really, it would just be symbolic, so it doesn't actually matter much... But this thread has just prompted me to realize that may be the case and I take pleasure in that possibility. Being debt-free at 40 would be a nice marker of seeming accomplishment.