Here is an interesting tidbit that I find very customer un-friendly.
If you have not logged in to your Arduino account in 24 months, they “may” lock your account. If you try to log in after this happens, you will be told “Wrong email/username or password“.

Obviously you will try “Forgot your password.” That will give you the message:
Check your email, we just sent you a link to complete the reset of your password.
…but no e-mail ever shows up.
Some searching revealed they were purging accounts that had not been accessed. I tried to create a new account. As soon as I entered my exciting username, it told me:
This username is reserved: the account was recently deleted for inactivity.
And that led me to contacting their support.
Support says…
Unfortunately, support cannot reinstate old accounts. You have to create a new account using a new e-mail address and a new username. They pointed out it is in the terms of service:

And thus, my account I have had since I first signed up in 2012…
https://forum.arduino.cc/u/allenhuffman/summary
…is now frozen in time, and I have no access to it.
Terms for thee, but not for me?
I last logged in in 2018 – which is over five years ago. Since all my data is still there, and still identified via my username, it looks like Arduino may be in violation of its own terms of service. ;-) They definitely did the part they say they “may” do (close an account for inactivity) but the rest, not so much. That is really frustrating with an account I started 14 years ago.
And, to make matters worse, I have used the same e-mail address since 1995. For me to create a new e-mail address just for this one site and then not have access to all my messages, etc. from the past 14 years is … unfortunate.
Perhaps getting back into Arduino this week was a bad idea ;-)
In conclusion…
Go log in to your Arduino account if you want to keep it.

Arduino makes some of the dumbest choices. It’s weird. I’ve had my account for ages but I never once used the forums. I was able log in without any issue. I guess now the clock is ticking.