No matter how happy you are at your job, you need to be interviewing regularly (numerous times a year) and exploring new partnerships and collaborators. Don’t make the mistake I see over and over with folks over 45 who’ve been suddenly laid off, and haven’t interviewed in 10 years.
Whatever age you are, you need the practice of communicating to hiring managers exactly why you’re amazing and why you should be hired. Secondly, even if you’re happy at your job, there are fabulous opportunities out there that you should be aware of and going for, to help you guide your career trajectory more authoritatively.