After I changed my job, I had to face the same old problem: I have to work for a project. I have to work 40 hours a week and each hour needs to be for a project.
Lets assume I prepare a talk for four hours and ten colleagues attend the 30 minute talk. So the company "looses" 9 man hours. If the company would save 15 hours because of the knowledge sharing, they would not care. It is easy to estimate time costs but hard to proof these time savings. So no project, no talk, no knowledge sharing.
So the only way to have talks and share knowledge is to sacrifice our spare time. But how to get my colleagues attending the talk, though they need to offer spare time as well? The solution is as simple as obvious. The speaker unfortunately offers his spare time to prepare the talk, but presents his talk during lunch break. We need to take a lunch break of at least 45 minutes, which is basically enough for a 30 minutes talk. And the colleagues can attend the talk, have their lunch during the talk and ask questions.
A colleague of mine and I started to have talks every two weeks. Lately we started to have weekly talks and invited the entire company, including the management. Surprisingly the management attended as well as 15 up to 25 of our colleagues. After a few months we had a real success: Another colleague wanted to have a talk and share something and he offered a few topics.
But why the effort and sacrifice spare time? Obviously we started to increase our value for the company especially for project managers and the management. On a second view we started to improve our presentation skills. But finally we could present our spare time studies and try to make the management invest into certain technology or knowledge -whereby we are the first-choice person to get the internal project ;). And at least with some non-technical topics, we even started to change internal processes (the first project uses a Kanban board combined with pomodoro).
So be a good leader and make others follow you.
Share your knowledge and change the world.
P.S: How leadership should work ... an explanation
P.P.S: Our slides can be found here (as long as they do not include too many "borrowed" slides)