My first encounter with this phrase exuding energy as well as the special charm of Latin happened in 2011. Such is the title of one of the episodes of the Canadian TV series Being Erica, in which the protagonist, thanks to the superpower of time travel her therapist Dr Tom possesses, learns to enjoy the present, without worrying about the past or future.
The phrase was coined by Horace in his poem ‘Tu ne quaesieris’, published in 23 BC. The verse is addressed to a lady worrying about her future. Its closing line reads: ‘Carpe diem, quam minimum credula postero’, which translates as, ‘Seize the day, trusting tomorrow as little as possible.’
So, carpe diem/ˌkɑːpeɪ ˈdiːɛm/ – you only live today once, so don’t waste it!