It's easy enough to be a celebrity, you just show up at parties and be in all the right places and get your photograph into magazines - that's really doable.
"It's much easier than fulfilling yourself as an actor, working on your acting and finding roles that are interesting, which is actually hard.
"When 'Friends' first took off, I thought my job was to be a celebrity and I started thinking, 'Hmmm, should I go to this party or to that one? Should I leave now or wait for a few minutes more?' And I tried it and I hated it - really, hated it.
"And then I realised that the one has nothing to do with the other. I could still be an actor without being a celebrity. I could still get the jobs I wanted to get and play the roles I wanted to play and I was also able to take my son to school and back and be home in the evenings for dinner with my husband too.
"So it was nice to be able to let go of the other stuff, which wasn't me at all."
Lisa will always be grateful to 'Friends' bosses because they were always happy for her to work on other projects alongside the show, so she was able to feel creatively fulfilled without getting frustrated.
She told Candis magazine "There's something nomadic about being an actor and if we feel stuck with just the one thing that we're allowed to do, we might start to go, 'Ugh', and feel frustrated.
"But I never felt that way because all while I was doing 'Friends', the producers let me go off and do independent films as well.
"I remember being very appreciative of that at the time, and thinking, 'Boy, this is the life.'