Unless you have been a victim of writing the wrong word of a Seed down or the incorrect order of it, you do not know how frustrating and desperate such a mistake can make you feel.
When creating a new Seed, always double check its validity. Not only by writing it down and double checking it with your own eyes. To me, even if the Wallet checks two or three words, it means nothing. There could always be an error and I try to minimize it.
The way I do it is as soon as I write down the Seed, I close the Wallet, then re launch it and use the Restore option. Enter the Seed from the paper I just wrote and go from there.
I wrote words in the wrong order before and at first glance it looked right. Next time I had to restore my Seed from my paper, it said it was wrong. I got desperate for days, until I tried to swap the word with the previous and luckily it did work for me.
Check your Seed twice. Do not be lazy.
This is a good reminder, perhaps this is trivial for many people, but it is important for the security of our wallets in the future. To be honest, I always do what you say every time I create a new wallet by writing a seed phrase and saving it. After that, I restored the wallet again and entered the seed phrase that had been saved. This is to ensure that the phrases we store are truly valid.
Because the seed phrase is very fatal if entered incorrectly, even if you write the wrong lower or upper case letter, we will fail to access our wallet. So it's true, as you said, it's better to check twice or three times before saving a seed phrase, especially in a wallet that we keep for the long term or the main wallet, of course we really need to be careful and thorough.