Lampard has worked primarily in the media since retiring from playing in 2017 following a glittering career that included three Premier League titles, four FA Cups and a Champions League at Chelsea.
His first competitive game in charge sees the Rams kick off the new Championship season against Reading at the Madejski Stadium on Friday.
Asked why he is back in football in a hands-on role, Lampard, 40, said: "Because you miss the bug.
"It (television work) is comfortable, but there is pressure there because you want to do the job as best as you can. But when you've been competitive for a long time as a player, you miss it.
"Myself and Steven (Gerrard) were talking about that openly last year when we were working on BT Sport. Football draws you back in and for all the 24-hours-a-day talk and lack-of-sleep talk you can't help but love it.
"This was something that I couldn't not do and I couldn't settle for that easy life when there was an opportunity to come and do this."
Gerrard is another former England international midfielder set to take charge of his first league game this weekend, at Scottish giants Rangers.
The ex-Liverpool captain has already overseen three Europa League games and remains unbeaten as a manager, winning twice.
Lampard added: "We were texting back and forth (on Tuesday), actually discussing the mad life of management and how we both see it.
"We are both the same, we are enjoying every minute of it. It's strange and you can't switch off because you want to do so well, that's certainly how I feel.
"Some days you can't switch off, which means giving it every moment of the day. I'm sure Steven will be the same because I know how competitive he is and I'm guessing if you ask him then he will give you some similar answers."