No matter how old you are - there's always something new to learn.
I've been working with the Atlassian products a LONG time (2006) 99% of the time on the server/data center platform, and now 1% cloud and yet there is always something new to learn.
When someone asks me how I know so much, I always answer that I don't know anything. I have found if i go into a situation, assuming nothing, then i always come out having learned something. Even if it's confirmation, cementing something I already knew.