Seems normal for 20-somethings, yes people did this in the 90s. Probably necessary in your 20s, to get varied experience and increase pay. 30-somethings can be more risk averse if they have young kids. By 40s and 50s, more chance someone knows what suits them and found a place that's a good fit and they want to stay, sometimes by then they have enough assets that they'll stay in a job they're happy even if pay is stagnant. 50s and older, do you really wanna do lots of job interviews, learn how a new company works? By the time you've done that a few times you lose appetite to keep doing it (not because you lose ambition, just, you know its not really gonna change your life and could be a bunch of hassle)