YES, YES, YES!!!! This is exactly what happened to me and I suspect it happens to most of us once we deviate from a rigid policy of No Sugar No Starch. I'm currently trying to undo the harm to myself that easing up has caused.

The whole problem is that you (meaning people) CAN have a cheat meal or a cheat day, not gain anything or just a bit of water weight that is soon gone, and you can get back on the wagon again immediately. What your brain has now learned is that you can eat a little bread/French fries/ice cream/cake etc. occasionally without consequences. The consequences show up later because now you know that you can get away with it again. And again.

The whole process happens so insidiously that you don't even realize you're pushing your luck. Eventually an extra lb shows up on the scale and doesn't go away, but it's just a lb, no big deal. One day you notice it's 3lbs that aren't going away. And all the time it's getting easier and easier to say ok to more carbs.

Whether or not people ever get back to strict low carb again depends upon how much weight gain shocks them into action. 10lbs, 15lbs, 100lbs? The lucky ones can be shocked into getting back to strict basics again. Sadly, this forum has seen more than it's fair share of people who were doing so well but eventually gained too much back and couldn't face starting over again.

I'm with ojoj: I've learned the hard way that I have to treat sugar and starch as though they were cigarettes and I can't even have a puff. (Spoken as a 4-pack-a-day addict who quit cold turkey 27 years ago and indeed has not had one puff since).