Think I probably pay more attention to the words as I get older, though it is sometimes harder to follow them because of hearing problems, poor diction, chopping the words up around a funky rhythmic accompaniment, or just too loud accompaniment.
One singing group tutor always made us READ the words of any new song we were learning, and then would tell us to "sing them as you'd say them", which avoids the odd scansions with elongated vowels which someone mentioned above.
And another quoted Hamish Henderson's advice to "let the words sit comfortably on the tune".
And if you are songwriting yourself and a particular phrase sounds awkward or doesn't ring true to normal speech, you can always re-write or turn it round.