Never help a child with a task at which he feels he can succeed

I observed a two year old today (2yrs and 2 months to be exact). He was playing with some manipulatives in a corner of a public office. His mum, myself, other adults and another child about his age were present but everyone was doing their own thing.
He played for a while with the first set of manipulatives and as he played, a few pieces fell off the table but no one said anything. When he was done, he picked up the pieces on the table, put them back into the container and took the container back to the shelf. He had not picked up the pieces on the floor…
At the shelf, he struggled with putting the container back because it had these rails you have to match the containers to. He struggled for a while, but none of the adults tried to help. We (his mum and I at least) just watched him. He finally got it on the shelf but not in the “correct” way at least not the way the manufacturer intended.
He then took another container with a different but similar kind of manipulatives and went back to the table to play with them. Once again, he finished, packed up, and went through the same process of getting the container into the shelf… he struggled for a while but finally got it in his own way. As he walked back to the table, this time without any container, he realized some of the manipulatives were on the floor. He proceeded to pick them, separate them and put them into the right containers. When he was done, he moved on to play with the other child. It was awesome to watch!

What was so interesting about this episode or why am I even writing about it?