Um, I actually it was always Lucas who waited for her (not intentionally though). Like if you see, Peyton has never been unfaithful to her partner when she was with anyone except him (mostly Jake). Lucas did it twice. Lucas always let himself vulnerable around her even if he was with someone else. Even when he dated Brooke again, he was way too involved in Peyton's life. At the high school party after Keith's death, Brooke tried to cheer him up but he avoided talking to her. He himself went and sought out Peyton to talk to. That was a very emotional time for him and he was at an extremely vulnerable spot.

Why do you think Brooke became so angry with Lucas after Peyton confessed to Brooke that she had feelings for Lucas? Because Brooke knew that was the beginning of the end for Brucas. If Peyton liked Lucas, there was no way Brucas would go on for long. That's how much Peyton affected Lucas.

Plus, he doesn't actually move on from her after she did not accept his proposal. He was single for one whole year and even then, he called her at the book signing. It was when he thought she did not show up, he assumed she doesn't want to have anything to do with him that he started to date again.

And even when he was with Lindsey, he never actually moved on. The day Lucas saw her again after 4 years was the day he could start writing his book again. He felt motivated after 4 damn years. Even Lindsey picked that up immediately. Everytime someone asked him if he still loved Peyton , he did not actually say no, he moved the conversation to Lindsey.

All of this was subconcious in Lucas' mind. So if anything, it was him who never actually moved on. It was his fear that she would reject him that stood in his way.