I don't think you ever forget someone who's shown an interest in you. Other people/things replace them, as a higher priority.

Many of us can relate to this situation. A guy has shown an interest, we've reciprocated, only to then see a different type of behaviour. Guys often say "see you later" or "see you around" as it's more casual than "goodbye". They don't realise the expectation it can attract. Of course, the other side is that they know full well what they're doing, so are players.

If you really want to draw a line under this experience, then perhaps revisit the place where he works. However, be prepared and accept that he may have already moved on in the work and relationship contexts. This could act as closure and you move on, you already have doubts anyway.

Hope this makes sense