I can't speak for the science of this, only my experience but I definitely struggled when I first started gaining when I was really skinny and a lot of it was just a mental thing. Like I had to train myself just to eat a healthy amount of food before I could even start eating an unhealthy amount in order to gain

I started out in high school when I was very underweight at 120 lbs. At first I just packed on muscle to get to a healthy weight, then after a few months of bulking I got a slight gut and realized I didn't just like the feeling of being muscular I just liked the feeling of being big. So since then I've dedicated myself to just making my body bigger whether its fat or muscle. I'm around 230 lbs now so I've definitely been successful in that goal but I just want to get so much bigger

Yes I love the feeling. I tried on a few of my favorite pants from only a year ago and they were so tight. Like they barely got around my ass and felt like boa constrictors around my thighs. It's just a nice benchmark to show you how much you've gained