It's not so much about "time", but rather mental bandwidth. It takes effort and energy, that you may not have if you have lots of things going on.

When people say they "don't have the time" this is often what they mean.

It's like the joke from Airplaine!: "Guess I picked a bad time to quit smoking", "Guess I picked a bad time to quit drinking", "Guess I picked a bad time to quit sniffing glue", "Guess I picked a bad time to quit amphetamines", etc.