We didn't have pudding every day at home growing up but we had something most days - cheap vanilla ice cream if not much else in - and we were VERY sugar oriented. Sugar on cereal, I used to take it in coffee, as you say as a reward, buying nice sweets as a treat (e.g. Thorntons toffee), and making sweets and biscuits as a family activity.
Then I met DH who has type 1 and saw just how much sugar I ate. When I visit my family it shocks me now, too.
I am much better now. I started off with 2 I think days each week without added sugar and now do 3. I do crave sweet stuff so I have dried fruit, fresh or stewed in winter, if I want to do baking it's sign scones with dried fruit/cheese/mashed bananas. DS is four and he knows sugar is a treat, we have fruit/yoghurt (mainly plain for the DC and something sweetened with fruit for me) as our everyday afters. We also have afters with lunch (that's what they do at nursery), not usually with tea, we would have our tea/biscuits/scone once they are in bed (sssh).
You do get used to it. It also helps a lot not to think "I can NEVER have sugar again, woe is me!". You just think "I'll have some trail mix for my snack today. I'll have one of those cookies on Saturday".
If I am going through a rough patch I do still see it as a reward though. DH pulls me up on it (he would NEVER comment on my weight but he is obviously very aware of sugar).
When I first started doing this I lost 3 stone plus (but I was also counting calories and upping the exercise).