This idiom can have a negative or positive aspect. Like all bragging or boasting, it depends on the situation and delivery as to the feeling of tooting one's own horn
In Idiom Scenario 1, the feeling is positive since Johnny has done such a good job for a teenager.
In Idiom Scenario 2, Gary is a bit of a braggart and so the feeling is somewhat negative.
This idiom is often used with not to
"toot your own horn" but
... In this form, the feeling can be more positive.
This idiom has the following variations. They all have the same meaning:
- to toot your own whistle
- to bang your own drum
- to beat your own drum
- to blow your own horn
- to blow your own trumpet