Can we really motivate ourselves "on-demand"? There are so many articles online and books selling on the idea that we should motivate ourselves daily, as motivation doesn't last long. Many cite numerous experiments and advise on techniques you can supposedly use, because some experiment showed positive results.

From all the popular psychology and life coaching books on Motivation, all I can gather is that motivation is something a person should think about constantly and regulate on their own, on a daily basis.(10 proven ways to motivate yourself,...and similar titles).

Can you really talk yourself into feeling motivated? Or is motivation something that just happens subconsciously? Is popular psychology really onto something or their claims too big? 

Edit: My question is not answered with the suggested answer in the comment section. I'm not interested in obstacles to motivation, I'm interested in whether one can consciously spark motivation within oneself, regardless of existing obstacles.
There is not much possibility to talk yourself into being motivated. However, personal narratives can help us redirect our motivations or manage them more productively. To take this more abstractly, consider a person who just ate a large meal. If they are not hungry, could they talk themselves into being hungry? (Rarely.) However, if a person is craving a certain type of food, they could notice that and consciously decide to redirect that interest into a different type of food, and then that intention might lead to actual behavior. This could also apply to longer-term goals, such as pursuing more education; but that process is only possible to the extent that other, existing motivations are borrowed to a new target. See https://en.wikipedia.org/wiki/Self-determination_theory for a popular theory of overall social motivations.

Motivation is not just subconscious, to the extent that we can have sensations around desire and goal states, e.g., be aware of urges and drives. All cognition includes subconscious processes: absolutely.

Popular psychology is wildly profitable but often quite unrelated to the latest empirical science. The incentive is to be convincing and be shared, not to be accurate. 'The Secret' is a good example: super popular and entirely inconsistent with physics. Finally, the note "...nobody can claim anything" is a bit vague.