system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does glue not stick to the inside of the bottle ?
gpt
The glue is dissolved in a solvent. When the glue is exposed to air, the solvent evaporates, leaving the glue to harden (and glue things together!).

Think of a bowl of salty water. The salt is our 'glue' and the water is our 'solvent'. Once the water evaporates, the salt will be left behind (and it will be in a different form, instead of dissolved in water, it will be crystalline. Similar to the glue!).