I'm 2.5 years out and I can tell you that although I had some restriction after surgery (mostly, I think due to the swelling of the wound and the time it takes to heal), by 6 months out I could eat what others could only do at 2+ years out (full chicken breast, some veggies, etc.). I never felt a restriction the same way that others have mentioned - I could move ahead much faster in trying new foods post-op than what was recommended (I didn't, but could have). Now I'm looking at getting a revision to bypass because clearly the restriction of the sleeve did not work for me. I know it's not just the sleeve, part of it was the mental side of things. For me, I've come to realise that there is no going back to normal eating patterns. The new food/portion control is for LIFE. Fail at that, the sleeve can fail (at least, it did in my case).
I remember the day after my surgery crying to one of my doctors that I didn't believe that they did the surgery (despite the scars and tubes and everything else) because I wasn't in any real pain, had no nausea, and was full of energy, the complete opposite to every other patient in the hospital when I was there. She told me I was one of the lucky ones that come out of surgery feeling good and that I should be thankful for it. She then showed me a picture of my stomach that was cut out (to prove it) and said that it was longer than usual. I sometimes wonder if, because of that, I didn't have the same restriction as others.
Anyway, long story short, everyone has a different reaction post-op to surgery. You may be someone who feels restriction years out so it will help you keep portions small. You may be someone who feels less restriction as time goes on, which means you have to have the mental strength and determination to stick to what is right, and not be distracted or influenced by others in what you eat. Either way, the best way to keep your sleeve small and unstretched to be vigilant in portion control and drinking protocols. Maybe forever.