My point's just that you had to adjust to there. If you're heavy enough and/or weak enough and you can't stand on your own, it'll be difficult getting to the point where you can, so you can just exercise those muscles. Possible, but annoying.
And body structure in general, bone lengths and all that, work better with some weights and not so well with others. Someone slight isn't made of pounds and pounds, whether through more gravity or muscles to support against more gravity.
You'd be surprised how startlingly fast a young man can grow muscle. There are a number of workout programs that claim to be able to take your squat from 135 lbs to 300 lbs in 3 months.
They work. I've done one.
Also: A regular fit person would still be able to stand up in 1.5G no problem. So, you get there, you start a daily workout program, you throw on slabs of muscle, you move on with life in your new home.
You move north of 2G's, things would be really really rough.