I was taught that the way of progress was neither swift nor easy.

I always try to do things that scare me a little bit.

量子理论的本质是否认用经典术语完整描述原子现象的可能性。

"Adventure is worthwhile in itself."

【原文】颜渊喟然叹曰：“仰之弥高，钻之弥坚；瞻之在前，忽焉在后。夫子循循然善诱人，博我以文，约我以礼，欲罢不能。既竭吾才，如有所立卓尔。虽欲从之，末由也已。”【译文】颜渊感叹地说：“(老师的道德和学问)抬头仰望，越仰望越觉得高耸，努力钻研，越钻研越觉得深厚；看着好象就在前面，忽然又像是在后面。老师步步引导，用知识丰富我，用礼法约束我，想停止前进都不能。我竭尽全力，仍然像有座高山矗立眼前，虽然我想攀上去，却没有途径。”

The only failure is not trying.