I would imagine my progression is not much different from other older divers. I was first certified by the LA County Underwater Unit in 1970 and dived actively in Southern California for 10 years. I did not log my dives and have a poor memory of depths and times. I had a SPG, a capillary depth gauge, and a watch. We dived Navy tables.
Skip ahead 17 years and I was recertified with my 12 year old son by PADI on Grand Cayman. Our cert dives were to 40, 40, 60, and 60 feet. Over the next 75 dives, 18 were over 100 feet, with a max of 121 feet. Finally, in 2004, at about 80 dives, I did AOW. My deep dive was to108 feet. We also finished Deep Diver with 3 more dives to 116,130, and 102 feet. The last dive was an unguided dive on a Grand Cayman wall, planned and executed by us. I was not asked for my AOW cert until about a year later in Key Largo. It certainly made diving much easier.
So, now, at over 1800 dives, I have over 300 dives below 100 ft, only about 30 below 130 feet. I very much appreciate
@Diving Dubai comment regarding Tec 40. Consistent with much of my other diving, I have done light deco without the benefit of additional training. About 5% of my diving includes less than 10, a maximum of 15 minutes of deco on back gas. 50% offers very little advantage over back gas for these dives, a couple of minutes. I do have redundant gas and usually dive solo. I have experience in a wide variety of environments and I am very comfortable with my dive profiles.
Very best and good diving,
Craig