Remembering Autocomplete Choice
The autocomplete is quite elaborate; when you choice to insert "program" when you have entered "pro", the selection will be different when, for instance, you have autocomplete after typing "pr".
Use Tab or Enter to Commit Auto Complete Selection
Use the following setting:
{ "auto_complete_commit_on_tab": false }
Auto completion with selectwill commit selection with either tab or enter.
Add Auto Complete Commit Keys:
Thanks to this web-page: https://sublimetext.userecho.com/communities/1/topics/4670-allow-setting-which-keys-commit-auto-complete for including instructions on how to add key-bindings so that you can commit auto-completion with more keys.
For example: commit auto complete selection with period:
{ "keys": ["."], "command": "commit_completion", "context": [{ "key": "auto_complete_visible" }, { "key": "setting.auto_complete_commit_on_tab", "operand": false }] }