It's not all black and white though. I did learn a lot (especially about myself in recent months), but this all came with a very real cost.
If I did consultancy or went back working full time as an employee, I'd have a ton more money in the bank. It does impact my family. It is money lost, no matter how you decide to look at it :)
I'm not saying that I regret doing what I did. What I regret (but am not going to cry all day about) is the bad decisions that I've made during that part of the journey.
Time is money, no double counting: either you can say you lost the time, or you can say you lost the money. Claiming you lost both would not be true in this case.
money not gained = money lost
To me that sounds like the perfect mentality for a burnout.
I would think that you used your time (i.e. opportunity) not for monetary but personal gains (i.e. experience).
Ideally you would have turned that experience into money again, but just because that didn't happen doesn't mean you didn't gain anything.