Up until I turned 50 I was the same. Now a couple of drinks will have an impact the following day.

The throughput of the liver for many of the enzymatic reactions that it performs, either for converting harmful chemical compounds into harmless substances, or for generating some conditionally-essential nutrients from precursors present in food, decreases in older people.

Because of this, when older, one should pay more attention to observing a healthy diet, which contains smaller amounts of harmful substances (e.g. alcohol) and enough quantities of all nutrients, including those that can be produced by a human body, but in insufficient quantities in older people (e.g. long-chain omega-3 fatty acids).

I'm in the same boat and recently read an article suggesting that with age, even one drink will have very detrimental effects on the whole night's sleep. The solution: have that drink or two much earlier, like 5 in the afternoon. I'm going to try it, but honestly it is in the evening that we want to drink.