I also am not fond of "back in the day". I am changing that to "back before I was gay", which would cover the time period prior to my conception in the fall of 1963. To refer to things that happened prior to my 16th birthday, I will say "back when I had no pay". For my college years, "back when I was to drunk to say". And for the time period covering my twenties and thirties, I like "back before I wasn't afraid to tell you what I weigh".
Random thought - I discovered that I am addicted to pre-sliced cheddar. I have my neighbor McCheesy to thank for this as she dropped off the aforementioned dairy item at our house last week. I've been throwing those tasty little squares down my gullet all week. Even last night, after coming home from a nice dinner, I had to have several slices (with a glass of milk mind you) prior to retiring to the bedroom. Cheese fries, cheese thighs, I've got hankering for the pre-sliced cheddar 'cause there is nothing better.