Intrinsic and extrinsic motivation are often misunderstood. I was only able to fully understand it after I came across the different Regulatory Styles matched up with Intrinsic and Extrinsic motivation.

Motivation

Regulation

example: "I exercise because...

extrinsic

external

...I get paid for it

introjected

...otherwise I'd feel ashamed

identified

...it is important for my body

integrated

...it reflects who I am and what I believe

intrinsic

intrinsic

...I enjoy the act of recycling

According to the definition, intrinsic motivation is only when you enjoy the act of doing something.

• Not when you think it's important.

• Not when you yourself freely choose it because you value the result.

• Not when you force yourself to do it, even though you don't want to

If you dislike doing it, it's not intrinsically motivated.

Extrinsic motivation is then any time you're motivated, but it's not intrinsic.

There is also Amotivation, which is when you're not motivated at all. So this is when you have neither intrinsic nor extrinsic motivation.

Why is this so often confused? Probably because intrinsic and extrinsic motivation sound a bit like internal and external motivation. And when you need to guess the then unknown term from the context, it's kinda good enough to translate it to the easy to understand internal/external terms. They are different though:

Motivation

Regulation

Perceived Locus of Causality

extrinsic

external

external

introjected

external-ish

identified

internal-ish

integrated

internal

intrinsic

intrinsic

internal

What about when I force myself to start something, but once doing it I kinda enjoy it?

It kinda sounds like 'the act of starting' is extrinsically motivated but 'the act of doing' is intrinsically motivated.

Why is this model useful?

Things that are intrinsically motivating, give me energy when doing them.

Extrinsically motivating things, don't give me (as much) energy.

But farther away from intrinsic motivation, I get less energy / it costs more energy.

In both cases I excluded the reflection/pat-on-the-shoulder stage, which can also create energy.

(src: Book: Understanding Motivation and Emotion 4th edition)