Never become too accomplished to become a beginner again.

Accomplishment makes beginning again harder, because you have further to fall in your own estimation and you are used to being competent. Many people stop learning new things at the point where they are good at one thing, and the narrowing happens quietly over decades.

Start something you will be bad at. A language, an instrument, a physical skill, anything where your existing standing is irrelevant. It keeps a capacity alive that atrophies otherwise, and it tends to make you noticeably better at working with people who are beginners in your own field.