The way I see it:
Our brains like to recognise patterns, this is an evolutionary trait of ours.
Acquiring knowledge gives us the understanding to identify more patterns
This manifests as that good feeling when something new clicks and it makes sense where it didn't before. Dopamine is the source of that good feeling and it's part of our brains' reward system to motivate us to do things that'll help us survive.
Chemically, the point of life is to do stuff that triggers our reward systems, and so we seek out the good feeling that comes with figuring stuff out like we seek out other sources of it.
So basically, the meaning of life is to enjoy life, and humans just enjoy learning