If you have seen my posts about bitcoin transaction confirmation before, you will know how I have recommended 1 confirmation in most of such related topics. But I recommend 6 this time to eliminate possible means that a transaction can be reversed. The more confirmations, the less a transaction can be reversed.
I commented on your post, this one. In this topic, you only had this one and it has inaccurate information. When you made a mistake, admit it and move on is not bad.
All transactions stored on bitcoin blockchain are valid and original after it is validated by nodes and having at least six confirmations.
Even 6 confirmations are not safe enough, it depends on the value of bitcoin you move in that transaction if you want more safety, you can wait till 9 or 12 confirmations, it's not a big deal to wait 30 or 60 more minutes.
On exchanges that allows one confirmation for deposit, they allow 2 or more confirmations before you can withdraw. Which means the exchanges do not accept one confirmation. Or can you name an exchange that allows one confirmation for withdrawal?
Of course, they require at least 1 confirmation for a deposit and for withdrawal, it will be more than 1, like 2 confirmations. Required confirmation for withdrawal will be more than the one for deposit. It is not more than 3 confirmations if I am not missing anything.
A first confirmation is most painful in waiting time, later confirmations will come naturally and more easily.