Are you sure this isn't "self sabotaging", ie not trying hard so that you can tell yourself that failure isn't because you're not smart enough but because you didn't actually try?
This can be a common coping mechanism for people with "fixed mindset". For an overview of the "fixed" vs "growth" mindset research, see e.g https://fs.blog/2015/03/carol-dweck-mindset/
(This is some really fascinating research and I've talked to lots of people who grew up as "smart kids" that feel this describes at least part of their personality.)
This can be a common coping mechanism for people with "fixed mindset". For an overview of the "fixed" vs "growth" mindset research, see e.g https://fs.blog/2015/03/carol-dweck-mindset/
(This is some really fascinating research and I've talked to lots of people who grew up as "smart kids" that feel this describes at least part of their personality.)