You said you want to be confident in your decision to marry before you do (paraphrasing a bit) - the other poster is saying that after a couple of decades it’s possible for you to change your mind about any decision no matter how confident you were at the time you made it.
Feel the same as what?
Feel the same about the decision I think is what is being suggested.
Feel the same about the decision as what?
As they did when they made it at a guess. Seems like fairly straightforward English.
Seems like quite confusing English (I still don’t get it).
You said you want to be confident in your decision to marry before you do (paraphrasing a bit) - the other poster is saying that after a couple of decades it’s possible for you to change your mind about any decision no matter how confident you were at the time you made it.