In theory, instead of creating a new wallet and memorising the seed, can I just choose words that are easy to remember and generate a wallet from that?

I recently bought a new computer so I installed Metamask again and imported the seed phrase. Looks like I accidentally added a wrong word and an empty wallet popped up.

Was this wallet already generated or did I just create a new wallet? If I created a new wallet, does that mean I can just choose easy words to remember from the BIP39 Word list?

I could put the words in any order that's easy for me to remember and then create a new wallet from that, instead of one being created for me?

I would still write the seed phrase down just to be safe, but if I can use specific words in a specific order that would be easier for me to memorize, why not?